From alan at batie.org Tue Feb 1 01:11:22 2005 From: alan at batie.org (Alan Batie) Date: Tue Feb 1 01:11:09 2005 Subject: [wxqc] Sensor mounting Message-ID: <41FF1D8A.4070801@batie.org> I've just put up pictures of my sensor mounting on my weather page (http://www.rdrop.com/mrtg/weather.html down at the bottom), and am open to suggestions for improvement, though that mounting is unlikely to change. A couple of things I note is that although there's no fans in the attic, it's probably not a good idea that the vent is right under the sensors, and the rain bucket shouldn't be under the anemometer arm, though I doubt that's really affecting it much. The qc graph shows my temperature being slightly high, though it could be a local difference, being where it is seems suspect. I'm not sure I had any real alternatives though: there are some pictures of the backyard at http://alan.batie.org/backyard/ (ignore the grand plans ;-) ). Phil also said the windspeed was high and the report shows lots of errors, and I'm not quite sure how it can figure that out, as variable as wind is. Given the way things are situated, I would expect the wind to report low, and I generally don't see near the wind the tv weather reports. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3196 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050131/fc3f2ed3/smime.bin From dshelms at comcast.net Tue Feb 1 07:04:27 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Tue Feb 1 07:04:33 2005 Subject: [wxqc] Sensor mounting In-Reply-To: <41FF1D8A.4070801@batie.org> Message-ID: Hi Alan, The anemometer is OK (may get some roof wind acceleration though as the wind is defkewcted up the roof line). Rooftop precip gauges are very problematic as the are in a high wind environment which causes significant rainfall under catchment as the rain is deflected over much of the gauge. The temp/rh gauge should be over the grass as roof materials will cause sampling problems. If possible, I'd remote keep the anemometer on the roof as is, but place the precip and temp/rh gauge on a free standing post about 6 feet inside the right hedge line in this picture: http://alan.batie.org/backyard/image002.htm The temp/rh at 5 feet AGL and the precip gauge on the same post, but on a horizontal bracket 1-2 feet away from the post and any possible splashing or shadowing from the temp/rh sensor. Hope this helps, Dave -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net]On Behalf Of Alan Batie Sent: Tuesday, February 01, 2005 1:11 AM To: wxqc@lists.gladstonefamily.net Subject: [wxqc] Sensor mounting I've just put up pictures of my sensor mounting on my weather page (http://www.rdrop.com/mrtg/weather.html down at the bottom), and am open to suggestions for improvement, though that mounting is unlikely to change. A couple of things I note is that although there's no fans in the attic, it's probably not a good idea that the vent is right under the sensors, and the rain bucket shouldn't be under the anemometer arm, though I doubt that's really affecting it much. The qc graph shows my temperature being slightly high, though it could be a local difference, being where it is seems suspect. I'm not sure I had any real alternatives though: there are some pictures of the backyard at http://alan.batie.org/backyard/ (ignore the grand plans ;-) ). Phil also said the windspeed was high and the report shows lots of errors, and I'm not quite sure how it can figure that out, as variable as wind is. Given the way things are situated, I would expect the wind to report low, and I generally don't see near the wind the tv weather reports. From alan at batie.org Tue Feb 1 12:29:00 2005 From: alan at batie.org (Alan Batie) Date: Tue Feb 1 12:28:52 2005 Subject: [wxqc] Sensor mounting In-Reply-To: References: Message-ID: <41FFBC5C.2040606@batie.org> Sandy and David Helms wrote: > If possible, I'd remote keep the anemometer on the roof as is, but place the > precip and temp/rh gauge on a free standing post about 6 feet inside the > right hedge line That's a good idea, thanks. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3196 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050201/af02e3e1/smime.bin From chris at yipyap.com Tue Feb 1 22:41:20 2005 From: chris at yipyap.com (Chris Howard) Date: Tue Feb 1 22:41:35 2005 Subject: [wxqc] BP correction In-Reply-To: <20050131214721.40141@amos>; from Chris Howard on Mon, Jan 31, 2005 at 09:47:21PM -0700 References: <20050131203318.25674@amos> <41FEFCDE.9000500@gladstonefamily.net> <20050131214721.40141@amos> Message-ID: <20050201204120.20488@amos> > > > Hmm, my goofball calculation gives me something around > 1015 mb. The calculation you suggest gives me 1051. > My neighboring CWOP stations are reporting figures > around 1030 mb. > > Maybe my raw reading is faulty? I dug out the manual for this thing, and there is a calibration procedure to set the BP value. Now the next question is, where do I get a "raw" value in inches of mercury that I can use for calibration? (Would one of those fine fellows in Boulder like to come up to Estes Park sometime and bring a calibrated barometer?) -- Chris Howard YipYap.Com chris@yipyap.com Estes Park, Colorado USA current Estes Park weather -- http://www.yipyap.com/wscurrent.html From dshelms at comcast.net Wed Feb 2 00:08:33 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Wed Feb 2 00:08:33 2005 Subject: [wxqc] BP correction In-Reply-To: <20050201204120.20488@amos> Message-ID: Hi Chris, Usually, we ask folks to set their pressure directly to a nearby airport altimeter on a calm wind afternoon. Altimeter is a convenient pressure value that doesn't require precise knowledge of your elevation or the reference pressure station's elevation. Again, we want altimeter pressure (not raw pressure or MSLP pressure). But.. you need to know a raw pressure, here you go. Estes Park is way high in the mountains, so you have to account for a low "station pressure" or the raw uncorrected pressure as a great deal of the Earth's atmosphere is below you. Here's the way I might try it: 1. Find a reliable pressure: In your case, Fort Collins (KFNL) is probably the closest calibrated pressure sensor. You can call the automated ASOS recording @ 970-669-9187 or get the altimeter off the Internet: Here's the pressure from the Aviation Weather Center ADDS: http://adds.aviationweather.noaa.gov/metars/index.php?station_ids=KFNL&std_t rans=translated&chk_metars=on KFNL 020435Z AUTO 01006KT 10SM FEW060 BKN065 M01/M08 A3032 RMK AO1 -- where A3032 is the Altimeter (30.32 inches of mercury) Assuming these is no big pressure gradients/differences between your location and Ft Collins 30 miles east of you, 2. Subtract the pressure between sea level and your elevation: Since altimeter is a sea level reduced pressure, you have to subtract off the pressure between sea level and your station elevation. I'm estimating your elevation in near 7,674 feet (the elevation of your hospital heliport in Estes Park). 1 foot = 0.001 inch of mercury 7674 feet * 0.001 inch / foot = 7.674 inches of pressure needed to be subtracted from the reference pressure at Ft Collins, 30.32 inches 30.32 inches - 7.674 inches = 22.646 inches or mercury, your raw station pressure. But, station pressure is usually expressed in millibars, Conversion ratio: 1.000 mb = 0.02953 inches 22.646 inches * (1 mb / 0.02953 inches) = 766.636 mb Hope this helps, Dave CW0351 P.S. The above procedure is a modified technique used to calibrate tactical barometers in the military. -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net]On Behalf Of Chris Howard Sent: Tuesday, February 01, 2005 10:41 PM To: Discussion of data quality issues Subject: Re: [wxqc] BP correction > > > Hmm, my goofball calculation gives me something around > 1015 mb. The calculation you suggest gives me 1051. > My neighboring CWOP stations are reporting figures > around 1030 mb. > > Maybe my raw reading is faulty? I dug out the manual for this thing, and there is a calibration procedure to set the BP value. Now the next question is, where do I get a "raw" value in inches of mercury that I can use for calibration? (Would one of those fine fellows in Boulder like to come up to Estes Park sometime and bring a calibrated barometer?) -- Chris Howard YipYap.Com chris@yipyap.com Estes Park, Colorado USA current Estes Park weather -- http://www.yipyap.com/wscurrent.html _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From dshelms at comcast.net Wed Feb 2 00:12:39 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Wed Feb 2 00:12:38 2005 Subject: [wxqc] BP correction In-Reply-To: Message-ID: redrum! -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net]On Behalf Of Sandy and David Helms Sent: Wednesday, February 02, 2005 12:09 AM To: Discussion of data quality issues Subject: RE: [wxqc] BP correction Hi Chris, Usually, we ask folks to set their pressure directly to a nearby airport altimeter on a calm wind afternoon. Altimeter is a convenient pressure value that doesn't require precise knowledge of your elevation or the reference pressure station's elevation. Again, we want altimeter pressure (not raw pressure or MSLP pressure). But.. you need to know a raw pressure, here you go. Estes Park is way high in the mountains, so you have to account for a low "station pressure" or the raw uncorrected pressure as a great deal of the Earth's atmosphere is below you. Here's the way I might try it: 1. Find a reliable pressure: In your case, Fort Collins (KFNL) is probably the closest calibrated pressure sensor. You can call the automated ASOS recording @ 970-669-9187 or get the altimeter off the Internet: Here's the pressure from the Aviation Weather Center ADDS: http://adds.aviationweather.noaa.gov/metars/index.php?station_ids=KFNL&std_t rans=translated&chk_metars=on KFNL 020435Z AUTO 01006KT 10SM FEW060 BKN065 M01/M08 A3032 RMK AO1 -- where A3032 is the Altimeter (30.32 inches of mercury) Assuming these is no big pressure gradients/differences between your location and Ft Collins 30 miles east of you, 2. Subtract the pressure between sea level and your elevation: Since altimeter is a sea level reduced pressure, you have to subtract off the pressure between sea level and your station elevation. I'm estimating your elevation in near 7,674 feet (the elevation of your hospital heliport in Estes Park). 1 foot = 0.001 inch of mercury 7674 feet * 0.001 inch / foot = 7.674 inches of pressure needed to be subtracted from the reference pressure at Ft Collins, 30.32 inches 30.32 inches - 7.674 inches = 22.646 inches or mercury, your raw station pressure. But, station pressure is usually expressed in millibars, Conversion ratio: 1.000 mb = 0.02953 inches 22.646 inches * (1 mb / 0.02953 inches) = 766.636 mb Hope this helps, Dave CW0351 P.S. The above procedure is a modified technique used to calibrate tactical barometers in the military. -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net]On Behalf Of Chris Howard Sent: Tuesday, February 01, 2005 10:41 PM To: Discussion of data quality issues Subject: Re: [wxqc] BP correction > > > Hmm, my goofball calculation gives me something around > 1015 mb. The calculation you suggest gives me 1051. > My neighboring CWOP stations are reporting figures > around 1030 mb. > > Maybe my raw reading is faulty? I dug out the manual for this thing, and there is a calibration procedure to set the BP value. Now the next question is, where do I get a "raw" value in inches of mercury that I can use for calibration? (Would one of those fine fellows in Boulder like to come up to Estes Park sometime and bring a calibrated barometer?) -- Chris Howard YipYap.Com chris@yipyap.com Estes Park, Colorado USA current Estes Park weather -- http://www.yipyap.com/wscurrent.html _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From chris at yipyap.com Wed Feb 2 12:18:31 2005 From: chris at yipyap.com (chris@yipyap.com) Date: Wed Feb 2 12:54:49 2005 Subject: [wxqc] more on BP calibration Message-ID: <200502021718.j12HIVEG005089@web156.megawebservers.com> Well I'm a little more enlightened and a little more confused. Using Phillip Gladstone's calculation for altitude correction gives me different numbers than using what I think David Helms was suggesting (0.001 inch per foot of elevation change). Comparing my station with Fort Collins, it looks to me like I'm currently somewhere between 0.69 and 0.89 high with my raw inches-of-mercury reading. Then I'm applying an altitude correction that leaves me with a reported mb figure that is somewhere around 10-20 mb low compared to the new other CW station in town. So if I calibrate my raw readings to be 0.79 lower and then use Phillip's altitude correction I would come out slightly higher than Fort Collins for reported mb figure. Is being +/- 0.1 inches of mercury considered close enough? I don't know how confident I am with the idea of comparing with Fort Collins. It's 30 miles away and on the plains at ~5000 feet. I'm in a high mountain park at ~7800 ft. But that does sound like the nearest calibrated point. Do these sensors drift over time? or you think I have been off by this much from the very beginning? (I bought the thing in 1996.) Chris Howard chris@yipyap.com From dshelms at comcast.net Wed Feb 2 14:54:39 2005 From: dshelms at comcast.net (dshelms@comcast.net) Date: Wed Feb 2 14:54:49 2005 Subject: [wxqc] more on BP calibration Message-ID: <020220051954.11366.42012FFF0000426100002C6622070016419C03040A089C0B@comcast.net> See comments below... Dave CW0351 > > Well I'm a little more enlightened and a little more confused. > > Using Phillip Gladstone's calculation for altitude correction > gives me different numbers than using what I think David Helms > was suggesting (0.001 inch per foot of elevation change). > --- see below on discussion of QCMS statistics. > Comparing my station with Fort Collins, it looks to me like > I'm currently somewhere between 0.69 and 0.89 high with my raw > inches-of-mercury reading. Then I'm applying an altitude > correction that leaves me with a reported mb figure that is > somewhere around 10-20 mb low compared to the new other CW > station in town. --- That CW is probably not calibrated yet (fact: at lest 25% of all CWOP stations get flagged for pressure issues, very problematic). The thing is, adjusting pressure is a rather trivial thing to do; unfortunately, people don't have enough information to make an accurate adjustment (the wrong answer is to listen to the radio). > > So if I calibrate my raw readings to be 0.79 lower and then > use Phillip's altitude correction I would come out slightly > higher than Fort Collins for reported mb figure. Is being > +/- 0.1 inches of mercury considered close enough? --- 00.03 inches or 1.0 mb of actual pressure is the target accuracy, I won't say +/- 00.10 inch is good or bad when looking at KFNL as atmospheric pressure variations may cause that difference to dramatically vary. At least it shows you are getting close. > > I don't know how confident I am with the idea of comparing > with Fort Collins. It's 30 miles away and on the plains at > ~5000 feet. I'm in a high mountain park at ~7800 ft. > But that does sound like the nearest calibrated point. --- That is what is available through the Internet anyway. Your elevation difference is similar to the Lararie (KLAR) and Cheyenne (KCYS) mountain vs. high plains situation elevation difference (I think they are 00.02 inches different today). If you have to use an airport that is more than 10 miles and a few hundred feet different elevation, do so with care. Always do your comparisons during light winds (high pressure) to minimize the pressure differences, especially when using a more distant "reference" pressure. You might try the Estes Park Medical Center's Heliport, 970-586-2317, and see if they have a calibrated altimeter for the inbound Medevacs (make sure they aren't busy!). > > Do these sensors drift over time? or you think I have > been off by this much from the very beginning? (I bought > the thing in 1996.) > --- Definitely. You should reaccomplish pressure calibration checks every 6 months or better. Hopefully, the QCMS data will give you a heads-up when things get out of whack. The problem with QCMS is it relies on your buddy station's pressures to create the "analysis" field, if the analysis includes several poorly calibrated pressures, then the analysis is not going to be very useful. That's why I say use a pressure sensor you know is professionally maintained which in most cases will be the local airport ASOS/AWOS. > Chris Howard > chris@yipyap.com > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050202/e1eafca9/attachment.html From dshelms at comcast.net Wed Feb 2 15:14:23 2005 From: dshelms at comcast.net (dshelms@comcast.net) Date: Wed Feb 2 15:14:27 2005 Subject: [wxqc] more on BP calibration Message-ID: <020220052014.23190.4201349C000006F400005A9622007347489C03040A089C0B@comcast.net> Skipped content of type multipart/alternative-------------- next part -------------- An embedded message was scrubbed... From: dshelms@comcast.net Subject: Re: [wxqc] more on BP calibration Date: Wed, 2 Feb 2005 19:54:55 +0000 Size: 684 Url: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050202/66e64e11/attachment.mht From chris at yipyap.com Wed Feb 2 17:17:50 2005 From: chris at yipyap.com (chris@yipyap.com) Date: Wed Feb 2 17:18:07 2005 Subject: [wxqc] Re: more on BP calibration Message-ID: <200502022217.j12MHoKl010603@web150.megawebservers.com> Thanks to both David and Phillip. I think I have a plan now. During the quiet part of the day today I could track my station with the Fort Collins METARS in a predictable way by subtracting 0.7 from my current raw figure (inches of mercury), then apply Phillip's altitude adjustment procedure. That worked until the breeze came up in Fort Collins. Even afterward it was pretty close, and on a gradient with the Fort Collins METARS and a CWOP station in between. I'm pretty convinced. I'm also convinced that the two other CWOP stations closest to me are slightly high in the BP department but not as far off kilter as I am! Chris Howard chris@yipyap.com From sam at wa4phy.net Wed Feb 9 21:05:21 2005 From: sam at wa4phy.net (Sam Drinkard) Date: Wed Feb 9 21:05:51 2005 Subject: [wxqc] Rain gauge discrepancy Message-ID: <420AC161.4030505@wa4phy.net> Altho this might not be strictly within the context of data quality, per-se, I wanted someone else' thoughts on this. Have noticed a decent amount of difference in the quantity of measured rain in my 8" NWS gauge vs. my Davis rain gauge, and the old 4" gauge. With today's rain event the 8" gauge contained 0.75", the Davis gauge recorded 0.62" and the 4" gauge had 0.65" in it. Are the 8" gauges really that much more accurate than a 4" or a tipping bucket that is properly calibrated? The 8" is located about 2' lower, but within 5' of the Davis gauge, and the 4" gauge is located out in the clear but 6' off the ground on the top of a privacy fence. Don't think there would be any turbulence from the house affecting the 8" or the Davis. Do I need to do some calibration on the tipping bucket? This is the 2nd or 3rd time I've noticed a relatively significant difference between the 8" NWS gauge and the Davis tipping bucket gauge. Comments? -- Sam From dshelms at comcast.net Thu Feb 10 00:46:10 2005 From: dshelms at comcast.net (dshelms@comcast.net) Date: Thu Feb 10 00:46:15 2005 Subject: [wxqc] Rain gauge discrepancy Message-ID: <021020050546.16724.420AF5220006CEA60000415422007637049C03040A089C0B@comcast.net> Hi Sam, Two things.... Its documented that tipping buckets can have trouble keeping up with moderate or greater rainfall with excess precip slopping over the cups. We are in the process of publishing siting guidelines for CWOP members. In the siting guide, we recommend that members site their precip gauge at 2.0 feet (0.6 meters) above ground level in an effort to minimize the very real problem of rainfall undercatchment caused by winds blowing up over the leading edge of the rain gauge. Wind speed increases rapidly with even small increases in elevation so it is very possible the cause of the precip differences. The the rule to follow is the lower you site your rain gauge, the better (the opposite of this concept is siting of rain gauges on rooftops is a bad idea). The qualifier if the lower is better rule is to make sure 1) rain falling outside the rain gauge doesn't splash into the gauge, and 2) adjacent trees, walls, and fences don't "shadow" the rain for your rain gauge. At 2 feet, you also need to keep the grass and creeping vines from overgrowing the gauge. We will have the CWOP Siting Guide out for the review in a couple weeks and hope ya'll will give it a good look. Regards, Dave -------------- Original message -------------- > Altho this might not be strictly within the context of data quality, > per-se, I wanted someone else' thoughts on this. > > Have noticed a decent amount of difference in the quantity of > measured rain in my 8" NWS gauge vs. my Davis rain gauge, and the old > 4" gauge. With today's rain event the 8" gauge contained 0.75", the > Davis gauge recorded 0.62" and the 4" gauge had 0.65" in it. Are the > 8" gauges really that much more accurate than a 4" or a tipping bucket > that is properly calibrated? The 8" is located about 2' lower, but > within 5' of the Davis gauge, and the 4" gauge is located out in the > clear but 6' off the ground on the top of a privacy fence. Don't think > there would be any turbulence from the house affecting the 8" or the > Davis. Do I need to do some calibration on the tipping bucket? This is > the 2nd or 3rd time I've noticed a relatively significant difference > between the 8" NWS gauge and the Davis tipping bucket gauge. > > Comments? > > -- > Sam > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050210/7102d051/attachment.html From ebookbinder at mchsi.com Wed Feb 9 21:17:49 2005 From: ebookbinder at mchsi.com (Evan Bookbinder) Date: Thu Feb 10 09:35:40 2005 Subject: [wxqc] Rain gauge discrepancy References: <420AC161.4030505@wa4phy.net> Message-ID: <044401c50f19$33dc1eb0$6701a8c0@HPLAPTOP> Sam, How heavy was the precipitation and what were the winds like? In addition the opening size differences, you may have differences that exist between a manually measured "can" and a tipping bucket. If it was precipitating heavy enough, it's possible that some of the "tips" in the Davis were missed. The design of the Davis gauges (not to distinguish from other home weather station gauges that are similar) also encourage splash-out. Based on what you've stated, I don't think siting is a problem, nor do I think the difference in guage diameter alone would lead to differences of that magnitude. As for me personally, I will always take the 8" gauge as official and use the automated guage as a way of estimating precipitation w/o having to go outside and check it. In most events I suspect that you notice the readings are similar. It's in extreme events or wintry precipitation where the differences are most significant. You can also check the accuracy of the Davis by taking a measured quantity of water from the NWS guage and pouring it through the Davis (of course disabling it from any logging features). Evan NWS Springfield MO ----- Original Message ----- From: "Sam Drinkard" To: "Discussion of data quality issues" Sent: Wednesday, February 09, 2005 8:05 PM Subject: [wxqc] Rain gauge discrepancy > Altho this might not be strictly within the context of data quality, > per-se, I wanted someone else' thoughts on this. > > Have noticed a decent amount of difference in the quantity of measured > rain in my 8" NWS gauge vs. my Davis rain gauge, and the old 4" gauge. > With today's rain event the 8" gauge contained 0.75", the Davis gauge > recorded 0.62" and the 4" gauge had 0.65" in it. Are the 8" gauges > really that much more accurate than a 4" or a tipping bucket that is > properly calibrated? The 8" is located about 2' lower, but within 5' of > the Davis gauge, and the 4" gauge is located out in the clear but 6' off > the ground on the top of a privacy fence. Don't think there would be any > turbulence from the house affecting the 8" or the Davis. Do I need to do > some calibration on the tipping bucket? This is the 2nd or 3rd time I've > noticed a relatively significant difference between the 8" NWS gauge and > the Davis tipping bucket gauge. > > Comments? > > -- > Sam > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > From sam at wa4phy.net Thu Feb 10 17:52:39 2005 From: sam at wa4phy.net (Sam Drinkard) Date: Thu Feb 10 17:52:46 2005 Subject: [wxqc] Rain gauge discrepancy In-Reply-To: <044401c50f19$33dc1eb0$6701a8c0@HPLAPTOP> References: <420AC161.4030505@wa4phy.net> <044401c50f19$33dc1eb0$6701a8c0@HPLAPTOP> Message-ID: <420BE5B7.1080506@wa4phy.net> Evan, Best I remember, there was little to no wind, so that kind of rules out the decapture part due to blowing, and there is an elevation difference of maybe 2' between the Davis and the SRG. As for the 4" gauge, it's about 6' or better off the ground, and I expect it to have some differences in readings due to height above ground, but not that different from the Davis gauge. I realize the tipping buckets are for sure, not optimal, but I don't recall seeing that much difference in it and the others until the last few rain events. I suppose I should try to calibrate with a known amount of water at a controlled rate to see if it is losing tips or just out of calibration. None of the rain came down with such intensity that it would have missed a tip I don't think, but anything is possible. I may lower it down to 2' like Dave suggested and then compare readings again. The whole reason I wound up with the 8" gauge was for snow measurement for the AGS area for CAE WFO. I'd not even bothered comparing things till our previous rain event. I'm currently out of town at the Orlando hamfest, so any replys might be delayed... Sam From dshelms at comcast.net Fri Feb 11 01:14:11 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Fri Feb 11 01:14:14 2005 Subject: [wxqc] Rain gauge discrepancy In-Reply-To: <420BE5B7.1080506@wa4phy.net> Message-ID: Sam, I keep a running comparison between my 4" manual gauge (4" is the minimum diameter manual rain gauge NWS will accept "climate" precip measurements from; as Evan says, 8" gauge is the "standard") and my Peet Bros automated heated rain gauge (its a electrode "shorting" gauge, the rain drops complete the circuit as they drip through the gauge's orifice and the gauge counts 0.001" per drop, no moving parts). My "best guess" monthly total precip for climate monitoring purposes is the greatest daily amount from either gauge which is often from the manual gauge. I encourage everyone to use a 4" or larger manual gauge to compare with the automated gauge. Don't use one of the cheaper "wedge" gauges, their diameter is too small. Many automated gauges have test procedures. Peet Bros recommends getting a liquid medicine syringe from your pharmacy (they are free) to carefully measure 10 milli-liters of water, place that amount of water into a paper cup with small pin holes and drain the water into the rain gauge to register a specific precip amount. Dave -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net]On Behalf Of Sam Drinkard Sent: Thursday, February 10, 2005 5:53 PM To: Discussion of data quality issues Subject: Re: [wxqc] Rain gauge discrepancy Evan, Best I remember, there was little to no wind, so that kind of rules out the decapture part due to blowing, and there is an elevation difference of maybe 2' between the Davis and the SRG. As for the 4" gauge, it's about 6' or better off the ground, and I expect it to have some differences in readings due to height above ground, but not that different from the Davis gauge. I realize the tipping buckets are for sure, not optimal, but I don't recall seeing that much difference in it and the others until the last few rain events. I suppose I should try to calibrate with a known amount of water at a controlled rate to see if it is losing tips or just out of calibration. None of the rain came down with such intensity that it would have missed a tip I don't think, but anything is possible. I may lower it down to 2' like Dave suggested and then compare readings again. The whole reason I wound up with the 8" gauge was for snow measurement for the AGS area for CAE WFO. I'd not even bothered comparing things till our previous rain event. I'm currently out of town at the Orlando hamfest, so any replys might be delayed... Sam _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From dshelms at comcast.net Fri Feb 11 07:25:17 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Fri Feb 11 07:25:35 2005 Subject: [wxqc] Rain gauge discrepancy In-Reply-To: Message-ID: One more thing... its very important that your rain gauge(s) are absolutely level. I use a 4 foot bubble level to do this. Dave -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net]On Behalf Of Sandy and David Helms Sent: Friday, February 11, 2005 1:14 AM To: Discussion of data quality issues Subject: RE: [wxqc] Rain gauge discrepancy Sam, I keep a running comparison between my 4" manual gauge (4" is the minimum diameter manual rain gauge NWS will accept "climate" precip measurements from; as Evan says, 8" gauge is the "standard") and my Peet Bros automated heated rain gauge (its a electrode "shorting" gauge, the rain drops complete the circuit as they drip through the gauge's orifice and the gauge counts 0.001" per drop, no moving parts). My "best guess" monthly total precip for climate monitoring purposes is the greatest daily amount from either gauge which is often from the manual gauge. I encourage everyone to use a 4" or larger manual gauge to compare with the automated gauge. Don't use one of the cheaper "wedge" gauges, their diameter is too small. Many automated gauges have test procedures. Peet Bros recommends getting a liquid medicine syringe from your pharmacy (they are free) to carefully measure 10 milli-liters of water, place that amount of water into a paper cup with small pin holes and drain the water into the rain gauge to register a specific precip amount. Dave -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net]On Behalf Of Sam Drinkard Sent: Thursday, February 10, 2005 5:53 PM To: Discussion of data quality issues Subject: Re: [wxqc] Rain gauge discrepancy Evan, Best I remember, there was little to no wind, so that kind of rules out the decapture part due to blowing, and there is an elevation difference of maybe 2' between the Davis and the SRG. As for the 4" gauge, it's about 6' or better off the ground, and I expect it to have some differences in readings due to height above ground, but not that different from the Davis gauge. I realize the tipping buckets are for sure, not optimal, but I don't recall seeing that much difference in it and the others until the last few rain events. I suppose I should try to calibrate with a known amount of water at a controlled rate to see if it is losing tips or just out of calibration. None of the rain came down with such intensity that it would have missed a tip I don't think, but anything is possible. I may lower it down to 2' like Dave suggested and then compare readings again. The whole reason I wound up with the 8" gauge was for snow measurement for the AGS area for CAE WFO. I'd not even bothered comparing things till our previous rain event. I'm currently out of town at the Orlando hamfest, so any replys might be delayed... Sam _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From tbarstow at earthlink.net Sun Feb 13 15:43:49 2005 From: tbarstow at earthlink.net (Tom Barstow) Date: Sun Feb 13 15:44:39 2005 Subject: [wxqc] QC Reports Message-ID: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> I'm new to this QC reporting and need some help. Below is a copy of my QC report and can anyone tell me what it's saying and how to fix the problem. I get this report all the time. I run a Davis Vantage Pro 2 with Virtual Weather Station as software. DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 12-FEB-2005 Errs CW2967 * 0/42 * 0/42 * 0/42 * 2/42 * 2/42 Note that times are in UTC. The values displayed are 'Observed (error)' The error value is 'analysis - observed'. I.e. if your observed value is higher than the computed value, then the error will be negative. You have to pick out the reading that is in error. The row with the time of 'Smry' is a daily summary and the data is 'mean(standard deviation)' for each observation during that day. DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 07-FEB-2005 Errs CW2967 * 0/96 * 3/96 * 0/96 * 0/96 * 0/96 From alan at batie.org Sun Feb 13 19:27:25 2005 From: alan at batie.org (Alan Batie) Date: Sun Feb 13 19:32:16 2005 Subject: [wxqc] QC Reports In-Reply-To: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> References: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> Message-ID: <420FF06D.6090404@batie.org> Tom Barstow wrote: > 12-FEB-2005 Errs CW2967 * 0/42 * 0/42 * 0/42 * 2/42 * 2/42 > > Note that times are in UTC. The values displayed are 'Observed (error)' > The error value is 'analysis - observed'. I think the problem is that the description doesn't match the report: if I remember right, it's more like "the values displayed are #errs/#num reports, where #errs is determined by comparing your data with a statistical analysis of neighboring weather stations". In looking at last week's weekly report I received: DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 06-FEB-2005 Errs CW2408 * * 0/95 * * 2/95 * 2/95 06-FEB-2005 Week CW2408 * *0.71(1.78)* *0.27(96.4)* -1.1( 1.6) The "Week" row (assuming it's the same as "Smry" only over a whole week) is supposed to be "mean(standard deviation)", but if anything, it looks more like "std dev (mean)". I'm not sure what "POT TEMP" is, but am assuming "DD" is "Degree Days" as I can't think what else it would be and I seem to recall hearing that term somewhere. Don't remember what they are though. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3196 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050213/058729bb/smime.bin From Evan.Bookbinder at noaa.gov Sun Feb 13 19:45:35 2005 From: Evan.Bookbinder at noaa.gov (Evan Bookbinder) Date: Sun Feb 13 19:50:02 2005 Subject: [wxqc] QC Reports In-Reply-To: <420FF06D.6090404@batie.org> References: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> <420FF06D.6090404@batie.org> Message-ID: <420FF4AF.2040002@noaa.gov> It's the number of errors and total number of reports for the period. In your case, you don't have any problems! FYI, POT TEMP is potential temperature. It's basically the result of taking everyone's temperature and putting them on an even surface (1000mb). This helps remove non-existant errors that would be caused by elevation differences. In otherwords, if I'm at 50 degrees and Joe is 10 miles away but 3000 feet higher elevation at 32 degrees, the potential temperature would still be nearly equal. DD is wind direction in degrees. I don't have your full report, but it sounds like there may be errors in the description fields that aren't matching up with the numbers that are shown. Hopefully someone in the know can take a look at this further. Evan WFO Springfield, MO Alan Batie wrote: > Tom Barstow wrote: > >> 12-FEB-2005 Errs CW2967 * 0/42 * 0/42 * 0/42 * 2/42 >> * 2/42 >> >> Note that times are in UTC. The values displayed are 'Observed (error)' >> The error value is 'analysis - observed'. > > > I think the problem is that the description doesn't match the report: > if I remember right, it's more like "the values displayed are > #errs/#num reports, where #errs is determined by comparing your data > with a statistical analysis of neighboring weather stations". > > In looking at last week's weekly report I received: > > DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD > * FF > * (MB) * (DEG F) * (DEG F) * (DEG) > * (KNT) > 06-FEB-2005 Errs CW2408 * * 0/95 * * 2/95 > * 2/95 > 06-FEB-2005 Week CW2408 * *0.71(1.78)* > *0.27(96.4)* -1.1( 1.6) > > The "Week" row (assuming it's the same as "Smry" only over a whole > week) is supposed to be "mean(standard deviation)", but if anything, > it looks more like "std dev (mean)". > > I'm not sure what "POT TEMP" is, but am assuming "DD" is "Degree Days" > as I can't think what else it would be and I seem to recall hearing > that term somewhere. Don't remember what they are though. > >------------------------------------------------------------------------ > >_______________________________________________ >wxqc mailing list >wxqc@lists.gladstonefamily.net >http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050214/b052f4f6/attachment.html From philip at gladstonefamily.net Sun Feb 13 20:04:28 2005 From: philip at gladstonefamily.net (Philip Gladstone) Date: Sun Feb 13 20:04:37 2005 Subject: [wxqc] QC Reports In-Reply-To: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> References: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> Message-ID: <420FF91C.5010207@gladstonefamily.net> Tom Barstow wrote: > I'm new to this QC reporting and need some help. Below is a copy of > my QC report and can anyone tell me what it's saying and how to fix > the problem. I get this report all the time. I run a Davis Vantage > Pro 2 with Virtual Weather Station as software. > > > DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD > * FF > * (MB) * (DEG F) * (DEG F) * (DEG) > * (KNT) > 12-FEB-2005 Errs CW2967 * 0/42 * 0/42 * 0/42 * 2/42 > * 2/42 The two rows in error are: C2967 * * * * -71 * 1 C2967 * * * * -60 * 6 I don't know what the limits are for wind speed and direction, but I would guess that 71 degrees probably exceeds the limit and 1 knot doesn't. The -60 degrees and 6 knot row -- I don't know which triggered the error. To be honest, I have not looked closely at the wind speed and direction QC information. DD is wind direction (I don't know why) FF is wind speed (I don't know why) I just stole the headings from the qc files that I pull from NOAA. Philip > > Note that times are in UTC. The values displayed are 'Observed (error)' > The error value is 'analysis - observed'. I.e. if your observed value > is higher > than the computed value, then the error will be negative. You have to > pick out > the reading that is in error. The row with the time of 'Smry' is a > daily summary > and the data is 'mean(standard deviation)' for each observation > during that day. > > > > DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD > * FF > * (MB) * (DEG F) * (DEG F) * (DEG) > * (KNT) > 07-FEB-2005 Errs CW2967 * 0/96 * 3/96 * 0/96 * 0/96 > * 0/96 > > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > -- Philip Gladstone * Check out the live pondcam at http://pond.gladstonefamily.net -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3322 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050213/a0579909/smime.bin From Michael.F.Barth at noaa.gov Mon Feb 14 18:31:17 2005 From: Michael.F.Barth at noaa.gov (Michael F Barth) Date: Mon Feb 14 18:31:48 2005 Subject: [wxqc] QC Reports In-Reply-To: <420FF91C.5010207@gladstonefamily.net> References: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> <420FF91C.5010207@gladstonefamily.net> Message-ID: The way the QC is done is that we take the wind speed and direction, then convert that to U (east-west) and V (north-south) vector components, and the QC is done separately on U and V. If either one of them fails the spatial consistency check then we mark both speed and direction as failed in the reports Philip processes into the summaries you receive. In any event, we've only flunked your wind obs 4 times in the last week, so I wouldn't worry about it. For more info on the QC see: http://www-sdd.fsl.noaa.gov/MSAS/qcms.html Thanks, Mike On Sun, 13 Feb 2005, Philip Gladstone wrote: > Tom Barstow wrote: > >> I'm new to this QC reporting and need some help. Below is a copy of my >> QC report and can anyone tell me what it's saying and how to fix the >> problem. I get this report all the time. I run a Davis Vantage Pro 2 >> with Virtual Weather Station as software. >> >> >> DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * >> FF >> * (MB) * (DEG F) * (DEG F) * (DEG) * >> (KNT) >> 12-FEB-2005 Errs CW2967 * 0/42 * 0/42 * 0/42 * 2/42 * >> 2/42 > > > The two rows in error are: > > C2967 * * * * -71 * 1 > C2967 * * * * -60 * 6 > I don't know what the limits are for wind speed and direction, but I would > guess that 71 degrees probably exceeds the limit and 1 knot doesn't. The > -60 degrees and 6 knot row -- I don't know which triggered the error. > > To be honest, I have not looked closely at the wind speed and direction > QC information. > DD is wind direction (I don't know why) > FF is wind speed (I don't know why) > > I just stole the headings from the qc files that I pull from NOAA. > > Philip > > > > >> >> Note that times are in UTC. The values displayed are 'Observed (error)' >> The error value is 'analysis - observed'. I.e. if your observed value is >> higher >> than the computed value, then the error will be negative. You have to >> pick out >> the reading that is in error. The row with the time of 'Smry' is a daily >> summary >> and the data is 'mean(standard deviation)' for each observation during >> that day. >> >> >> >> DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * >> FF >> * (MB) * (DEG F) * (DEG F) * (DEG) * >> (KNT) >> 07-FEB-2005 Errs CW2967 * 0/96 * 3/96 * 0/96 * 0/96 * >> 0/96 >> >> >> _______________________________________________ >> wxqc mailing list >> wxqc@lists.gladstonefamily.net >> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >> >> > > > -- > Philip Gladstone > * Check out the live pondcam at http://pond.gladstonefamily.net > > From dray at adelphia.net Sat Feb 19 11:49:58 2005 From: dray at adelphia.net (Gary DiLorenzo) Date: Sun Feb 20 09:17:00 2005 Subject: [wxqc] Barometric Pressure Readings Message-ID: <003b01c516a3$0c5a4510$4f3f3218@garys> This is my setup: Davis Instruments Wireless Weather Monitor II WeatherLink 5.4 Software To set my barometer it asks for my Station Elevation and Sea-Level Barometer. I set my Station Elevation to 1090ft and I set Sea-Level Barometer from this site http://weather.unisys.com/surface/sfc_con_pres.html. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050219/b4731514/attachment.html From philip at gladstonefamily.net Mon Feb 21 13:49:33 2005 From: philip at gladstonefamily.net (Philip Gladstone) Date: Mon Feb 21 13:49:46 2005 Subject: [wxqc] Barometric Pressure Readings In-Reply-To: <003b01c516a3$0c5a4510$4f3f3218@garys> References: <003b01c516a3$0c5a4510$4f3f3218@garys> Message-ID: <421A2D3D.4080405@gladstonefamily.net> Gary, The values that you are reporting to CWOP are 34 millibars too low. This is almost exactly the amount if the altitude compensation was not being performed. Can you check your sea-level reading at your station, and then check the values shown at http://www.findu.com/cgi-bin/wx.cgi?call=CW2493 If the two values do not agree, then it implies that there is some more entries that need to be made into your software, or else the software has a problem. Philip Gary DiLorenzo wrote: > > This is my setup: > > Davis Instruments Wireless Weather Monitor II > WeatherLink 5.4 Software > > To set my barometer it asks for my Station Elevation and Sea-Level > Barometer. I set my Station Elevation to 1090ft and I set Sea-Level > Barometer from this site > http://weather.unisys.com/surface/sfc_con_pres.html. > > > > > ------------------------------------------------------------------------ > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3322 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050221/0fe808db/smime.bin From oldrhinebeck at comcast.net Thu Feb 24 11:24:58 2005 From: oldrhinebeck at comcast.net (Palen M. Elder) Date: Thu Feb 24 11:25:02 2005 Subject: [wxqc] Another QC Report Question Message-ID: Hi to all! I have been a member since September 2004 and am just now trying to make sure the data that I am submitting is accurate (better late than never). I have the following hardware and software: Davis Wireless Vantage PRO Virtual Weather Station - Internet Edition v12.07 p31 VWSaprs v1.9.4.0 I have been reviewing the graphs for my station at : http://pond1.gladstonefamily.net:8080/cgi-bin/wxqchart.pl?site=C2539 over the past week along with the Weather Quality reports that have been e-mailed to me on a daily basis, an example of which follows: DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 22-FEB-2005 2345 CW2539 *1020.(0.64)* 31(-11.)*25.9(1.36)*311.(18.2)*3.48( 0.3) 23-FEB-2005 0001 CW2539 *1020.(0.29)* 31(-11.)*26.2(1.07)*336.(-6.8)*1.74(2.04) 23-FEB-2005 0016 CW2539 *1021.(-0.2)* 30(-10.)*25.8(1.47)*349.(-19.)*2.61(1.17) 23-FEB-2005 0031 CW2539 *1021.(-0.7)* 30(-10.)*25.8(1.47)*337.(-7.8)*0.87( 2.9) 23-FEB-2005 0047 CW2539 *1021.(-0.7)* 30(-10.)*26.6(0.62)* 0(-52.)* 0(3.77) 23-FEB-2005 0102 CW2539 *1021.(0.27)* 31(-11.)* 27( -0)*312.(20.1)*0.87(1.57) 23-FEB-2005 0117 CW2539 *1022.(0.17)* 31(-11.)*27.6(-0.6)*343.(-10.)*0.87(1.57) 23-FEB-2005 0133 CW2539 *1022.( -0)* 31(-11.)*26.7(0.25)*313.(19.1)*1.74( 0.7) 23-FEB-2005 0148 CW2539 *1022.( -0)* 31(-11.)*27.6(-0.6)*342.(-9.9)*2.61(-0.2) 23-FEB-2005 0203 CW2539 *1022.(0.24)* 31(-11.)* 27(0.25)*344.(-24.)*4.34(-0.8) 23-FEB-2005 0219 CW2539 *1022.(0.04)* 31(-11.)* 27(0.25)*340.(-20.)*2.61(0.93) 23-FEB-2005 0234 CW2539 *1022.(-0.2)* 31(-11.)*26.2(1.12)*360.(-40.)*1.74( 1.8) 23-FEB-2005 0249 CW2539 *1023.(0.16)* 30(-10.)*25.5(0.84)* 7(-37.)*0.87(1.27) 23-FEB-2005 0304 CW2539 *1023.(0.04)* 30(-10.)*25.2(1.14)*359.(-29.)*4.34(-2.2) 23-FEB-2005 0320 CW2539 *1023.(-0.2)* 30(-10.)*24.9(1.43)*326.(3.81)*1.74( 0.4) 23-FEB-2005 0335 CW2539 *1023.(-0.2)* 30(-10.)*25.8(0.56)*323.(6.81)*2.61(-0.5) 23-FEB-2005 0345 CW2539 *1023.(-0.2)* 30(-10.)*25.2(1.14)*360.(-30.)*1.74( 0.4) 23-FEB-2005 0401 CW2539 *1023.(0.22)* 30(-12.)*25.5(-0.1)*332.(7.39)*1.74(0.38) 23-FEB-2005 0416 CW2539 *1023.(-0.1)* 30(-12.)*26.1(-0.6)* 0(-42.)* 0(2.12) 23-FEB-2005 0432 CW2539 *1024.(-0.1)* 29(-11.)*24.8(0.65)*350.(-10.)*1.74(0.38) 23-FEB-2005 0447 CW2539 *1024.(-0.1)* 28(-10.)*23.8(1.63)*315.(24.4)*1.74(0.38) 23-FEB-2005 0502 CW2539 *1024.( 0.1)* 28(-10.)*23.8(1.25)*357.(-17.)*0.87(1.17) 23-FEB-2005 0518 CW2539 *1024.(-0.1)* 28(-10.)*23.5(1.53)*360.(-20.)*0.87(1.17) 23-FEB-2005 0533 CW2539 *1024.(-0.3)* 28(-10.)*23.5(1.53)*354.(-14.)*1.74( 0.3) 23-FEB-2005 0549 CW2539 *1024.(-0.6)* 28(-10.)*23.2(1.82)* 0(-41.)* 0(2.04) 23-FEB-2005 0604 CW2539 *1024.(0.25)* 28(-11.)*23.5(0.15)* 0(-36.)* 0(3.09) 23-FEB-2005 0619 CW2539 *1024.(0.05)* 27(-10.)*23.1(0.57)* 0(-36.)* 0(3.09) 23-FEB-2005 0635 CW2539 *1025.(-0.1)* 27(-10.)*22.8(0.85)* 0(-36.)* 0(3.09) 23-FEB-2005 0650 CW2539 *1025.(-0.2)* 27(-10.)*22.5(1.13)* 13(-28.)*2.61(0.48) 23-FEB-2005 0700 CW2539 *1025.(-0.2)* 26(-10.)*22.7(-0.2)* 0(-28.)* 0(1.81) 23-FEB-2005 0716 CW2539 *1025.(-0.2)* 26(-10.)*22.4(0.11)* 31(-37.)*0.87(0.94) 23-FEB-2005 0731 CW2539 *1025.(-0.3)* 26(-10.)*21.6(0.95)* 0(-28.)* 0(1.81) 23-FEB-2005 0747 CW2539 *1025.(-0.3)* 25(-9.3)*20.6(1.93)* 0(-28.)* 0(1.81) 23-FEB-2005 0802 CW2539 *1025.(0.21)* 25(-12.)*20.6(0.17)*360.(-26.)*0.87(0.67) 23-FEB-2005 0817 CW2539 *1025.(0.01)* 25(-12.)*20.9(-0.1)* 0(-48.)* 0(1.54) 23-FEB-2005 0833 CW2539 *1025.(0.19)* 24(-11.)*19.9(0.87)* 0(-48.)* 0(1.54) 23-FEB-2005 0848 CW2539 *1025.( -0)* 24(-11.)*19.9(0.87)* 0(-48.)* 0(1.54) 23-FEB-2005 0904 CW2539 *1025.(-0.1)* 24(-13.)*20.2(-0.5)* 0(-71.)* 0(1.08) 23-FEB-2005 0919 CW2539 *1025.( -0)* 24(-13.)*20.4(-0.8)* 0(-71.)* 0(1.08) 23-FEB-2005 0935 CW2539 *1025.(0.09)* 24(-13.)*20.2(-0.5)* 0(-71.)* 0(1.08) 23-FEB-2005 0950 CW2539 *1025.(-0.1)* 23(-12.)*18.9(0.74)* 0(-71.)* 0(1.08) 23-FEB-2005 1001 CW2539 *1026.(0.03)* 22(-12.)*18.2(-0.3)* 0(-86.)* 0(1.42) 23-FEB-2005 1016 CW2539 *1026.(-0.4)* 21(-11.)*17.5(0.43)* 0(-86.)* 0(1.42) 23-FEB-2005 1032 CW2539 *1026.(-0.5)* 21(-11.)*17.8(0.16)*357.(-62.)*0.87(0.55) 23-FEB-2005 1047 CW2539 *1026.(-0.8)* 20(-10.)*16.8(1.14)* 0(-86.)* 0(1.42) 23-FEB-2005 1103 CW2539 *1026.(-0.1)* 19(-12.)*15.8(0.82)*357.(39.7)*0.87(-0.2) 23-FEB-2005 1118 CW2539 *1027.(-0.3)* 20(-13.)* 17(-0.4)*333.(63.7)*0.87(-0.2) 23-FEB-2005 1134 CW2539 *1027.(-0.4)* 20(-11.)*17.3(-0.7)*315.(81.7)*0.87(-0.2) 23-FEB-2005 1149 CW2539 *1027.(-0.7)* 20(-13.)*17.3(-0.7)* 0(-48.)* 0(0.64) 23-FEB-2005 1205 CW2539 *1027.(-0.3)* 19(-11.)* 16(0.55)* 0(-48.)* 0(0.64) 23-FEB-2005 1220 CW2539 *1027.(-0.3)* 19(-11.)* 16(0.55)*315.(17.9)*0.87(-0.2) 23-FEB-2005 1230 CW2539 *1027.(-0.3)* 18(-12.)*14.8(1.79)* 0(-48.)* 0(0.64) 23-FEB-2005 1246 CW2539 *1027.(-0.6)* 18(-12.)*14.8(1.79)* 0(-48.)* 0(0.64) 23-FEB-2005 1302 CW2539 *1027.(-0.4)* 18(-12.)*15.1(-0.1)* 0(-121.)* 0(0.11) 23-FEB-2005 1317 CW2539 *1027.(-0.4)* 19(-13.)*16.6(-1.6)*270.(-9.8)*1.74(-1.6) 23-FEB-2005 1333 CW2539 *1028.(-0.7)* 19(-13.)*16.3(-1.3)*265.(-4.8)*2.61(-2.5) 23-FEB-2005 1348 CW2539 *1027.(-0.5)* 19(-13.)*16.6(-1.6)*299.(-38.)*0.87(-0.8) 23-FEB-2005 1404 CW2539 *1027.(-0.5)* 19(-9.2)*16.3(2.54)* 0(-33.)* 0(0.68) 23-FEB-2005 1420 CW2539 *1027.(-0.4)* 20(-10.)* 17(1.81)* 0(-33.)* 0(0.68) 23-FEB-2005 1433 CW2539 *1027.(-0.3)* 21(-11.)* 18(0.82)* 0(-33.)* 0(0.68) 23-FEB-2005 1448 CW2539 *1027.(-0.3)* 25(-14.)*21.1(-2.3)* 0(-33.)* 0(0.68) 23-FEB-2005 1503 CW2539 *1027.(-0.3)* 28(-11.)*21.7(-2.1)*319.(14.7)*0.87(0.37) 23-FEB-2005 1518 CW2539 *1027.(-0.3)* 29(-12.)*20.5(-0.8)*298.(35.7)*0.87(0.37) 23-FEB-2005 1533 CW2539 *1027.(-0.6)* 27(-12.)*19.2(0.44)*281.(52.7)*0.87(0.37) 23-FEB-2005 1548 CW2539 *1027.(-0.2)* 29(-14.)*20.8(-1.2)*320.(13.7)*0.87(0.37) 23-FEB-2005 1603 CW2539 *1027.( -0)* 32(-12.)*23.3(-3.8)* 0(-19.)* 0(0.58) 23-FEB-2005 1618 CW2539 *1026.(0.26)* 36(-17.)* 21(-1.5)* 0(-19.)* 0(0.58) 23-FEB-2005 1633 CW2539 *1026.(0.36)* 37(-18.)*20.1(-0.6)*322.(40.1)*2.61( -2) 23-FEB-2005 1648 CW2539 *1026.(-0.2)* 39(-18.)*20.5(-2.1)* 0(-80.)* 0(0.68) 23-FEB-2005 1703 CW2539 *1026.(0.08)* 38(-17.)*19.6(-1.2)* 0(-80.)* 0(0.68) 23-FEB-2005 1718 CW2539 *1026.(0.08)* 38(-17.)*20.6(-2.1)*359.(-57.)*4.34(-3.7) 23-FEB-2005 1733 CW2539 *1026.(0.28)* 39(-18.)*19.5(-1.1)*309.(-7.5)*2.61(-1.9) 23-FEB-2005 1748 CW2539 *1026.(0.38)* 34(-13.)*15.9(2.51)*253.(48.5)*2.61(-1.9) 23-FEB-2005 1803 CW2539 *1026.(-0.2)* 34(-12.)*19.1(-2.4)*248.(41.7)*4.34(-2.5) 23-FEB-2005 1818 CW2539 *1026.(-0.2)* 32(-10.)*15.9(0.77)*253.(36.7)*2.61(-0.8) 23-FEB-2005 1833 CW2539 *1025.( -0)* 31(-9.7)*17.2(-0.5)*246.(43.7)*0.87(0.99) 23-FEB-2005 1848 CW2539 *1025.( 0.2)* 32(-10.)*18.5(-1.8)* 0(-92.)* 0(1.86) 23-FEB-2005 1903 CW2539 *1025.(-0.1)* 34(-13.)*17.3(-1.4)*346.(-44.)*2.61(-0.8) 23-FEB-2005 1918 CW2539 *1025.( -0)* 32(-12.)*18.5(-2.6)*344.(-42.)*2.61(-0.8) 23-FEB-2005 1933 CW2539 *1025.(-0.2)* 33(-13.)*18.6(-2.7)*315.(-13.)*4.34(-2.6) 23-FEB-2005 1948 CW2539 *1025.(-0.1)* 32(-12.)*18.1(-2.1)*350.(-48.)*1.74(0.02) 23-FEB-2005 2003 CW2539 *1025.(-0.3)* 32(-12.)*18.1(-2.2)* 0(-71.)* 0(1.69) 23-FEB-2005 2018 CW2539 *1025.(-0.1)* 31(-11.)*14.6(1.33)* 0(-71.)* 0(1.69) 23-FEB-2005 2033 CW2539 *1025.(-0.1)* 31(-11.)*16.8(-0.8)*318.(-7.2)*1.74( -0) 23-FEB-2005 2048 CW2539 *1024.(0.08)* 32(-12.)*16.4(-0.5)* 0(-71.)* 0(1.69) 23-FEB-2005 2103 CW2539 *1024.(-0.4)* 32(-12.)*17.3(-0.3)*342.( 24)*0.87(0.44) 23-FEB-2005 2118 CW2539 *1025.(-0.6)* 32(-12.)*20.9(-3.9)* 0(-15.)* 0(1.31) 23-FEB-2005 2133 CW2539 *1024.(-0.4)* 32(-12.)*20.5(-3.5)* 28(-22.)*0.87(0.44) 23-FEB-2005 2148 CW2539 *1024.(-0.3)* 31(-11.)*17.6(-0.6)* 0(-15.)* 0(1.31) 23-FEB-2005 2203 CW2539 *1024.(-0.1)* 30(-10.)*18.2(-1.4)* 56(36.5)*0.87(-0.3) 23-FEB-2005 2218 CW2539 *1025.(-0.5)* 28(-8.9)*17.8( -1)*143.(-50.)*5.21(-4.7) 23-FEB-2005 2233 CW2539 *1025.(-0.6)* 27(-7.9)*18.5(-1.8)*145.(-52.)*3.48(-2.9) 23-FEB-2005 2248 CW2539 *1025.(-1.1)* 27(-7.9)*19.2(-2.4)*127.(-34.)*0.87(-0.3) 23-FEB-2005 2303 CW2539 *1025.(-0.7)* 26(-7.3)*19.8(-1.8)*113.(-10.)*1.74(-0.1) 23-FEB-2005 2318 CW2539 *1025.(-0.7)* 26(-7.4)*19.8(-1.8)* 0(81.2)* 0(1.63) 23-FEB-2005 2333 CW2539 *1025.(-0.7)* 26(-7.4)*19.5(-1.5)*145.(-42.)*1.74(-0.1) 23-FEB-2005 2348 CW2539 *1025.(-1.1)* 26(-7.4)*19.8(-1.8)* 0(81.2)* 0(1.63) 23-FEB-2005 Errs CW2539 * 0/97 * 8/97 * 0/97 * 0/97 * 0/97 23-FEB-2005 Smry CW2539 *-0.2(0.32)*-11.(2.11)*-0.2(1.43)*-21.(40.8)*0.48(1.44) I originally determined my elevation using a handheld GPS to be 900' MSL. Over the past week I have determined that the elevation is actually 870' MSL. I have correct the elevation in the hardware and software and now the barometer readings seem to be within acceptable limits. I am know focusing my attention on the temperature readings. My readings, according to the graphs and reports, seem to indicate that the Potential Temperature reading is consistently 10 to 12 degrees high. I know my temperature readings are occasionally high due to the placement of the sensor array (I plan to move it to another location this spring), but when I look at other stations in my area (airports - KPTK, K7D2, KDET, and KMTC) my readings seem to be off only 3 to 4 degrees. In analyzing the Weather Quality report, if I am interpreting it correctly, it indicates that I only have 8 errors out of 97 readings. Can anyone with experience in this matter please tell me what I am doing wrong/right? Thanks for your help, -Palen CW2539 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050224/65e5ea01/attachment.html From Michael.F.Barth at noaa.gov Thu Feb 24 11:40:34 2005 From: Michael.F.Barth at noaa.gov (Michael F Barth) Date: Thu Feb 24 11:41:09 2005 Subject: [wxqc] Another QC Report Question In-Reply-To: <20050224162540.044F032000A@noaaczspam03.nems.noaa.gov> References: <20050224162540.044F032000A@noaaczspam03.nems.noaa.gov> Message-ID: Palen, I'm amazed your temperature QC is as good as it is (10% failure) given that a) the QC is done on potential temperature, and elevation is used in the conversion, and b) our station table has you listed at 900 meters, when it should have been 900 ft! Russ: He's now measured his elevation to be 870 ft, so please update the station table to 265.176 meters. Thanks, Mike On Thu, 24 Feb 2005, Palen M. Elder wrote: > Hi to all! > > I have been a member since September 2004 and am just now trying to make > sure the data that I am submitting is accurate (better late than never). I > have the following hardware and software: > > Davis Wireless Vantage PRO > Virtual Weather Station - Internet Edition v12.07 p31 > VWSaprs v1.9.4.0 > > I have been reviewing the graphs for my station at : > http://pond1.gladstonefamily.net:8080/cgi-bin/wxqchart.pl?site=C2539 over > the past week along with the Weather Quality reports that have been e-mailed > to me on a daily basis, an example of which follows: > > DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF > > * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) > > 22-FEB-2005 2345 CW2539 *1020.(0.64)* 31(-11.)*25.9(1.36)*311.(18.2)*3.48( > 0.3) > > 23-FEB-2005 0001 CW2539 *1020.(0.29)* > 31(-11.)*26.2(1.07)*336.(-6.8)*1.74(2.04) > > 23-FEB-2005 0016 CW2539 *1021.(-0.2)* > 30(-10.)*25.8(1.47)*349.(-19.)*2.61(1.17) > > 23-FEB-2005 0031 CW2539 *1021.(-0.7)* 30(-10.)*25.8(1.47)*337.(-7.8)*0.87( > 2.9) > > 23-FEB-2005 0047 CW2539 *1021.(-0.7)* 30(-10.)*26.6(0.62)* 0(-52.)* 0(3.77) > > 23-FEB-2005 0102 CW2539 *1021.(0.27)* 31(-11.)* 27( > -0)*312.(20.1)*0.87(1.57) > > 23-FEB-2005 0117 CW2539 *1022.(0.17)* > 31(-11.)*27.6(-0.6)*343.(-10.)*0.87(1.57) > > 23-FEB-2005 0133 CW2539 *1022.( -0)* 31(-11.)*26.7(0.25)*313.(19.1)*1.74( > 0.7) > > 23-FEB-2005 0148 CW2539 *1022.( -0)* > 31(-11.)*27.6(-0.6)*342.(-9.9)*2.61(-0.2) > > 23-FEB-2005 0203 CW2539 *1022.(0.24)* 31(-11.)* > 27(0.25)*344.(-24.)*4.34(-0.8) > > 23-FEB-2005 0219 CW2539 *1022.(0.04)* 31(-11.)* > 27(0.25)*340.(-20.)*2.61(0.93) > > 23-FEB-2005 0234 CW2539 *1022.(-0.2)* 31(-11.)*26.2(1.12)*360.(-40.)*1.74( > 1.8) > > 23-FEB-2005 0249 CW2539 *1023.(0.16)* 30(-10.)*25.5(0.84)* > 7(-37.)*0.87(1.27) > > 23-FEB-2005 0304 CW2539 *1023.(0.04)* > 30(-10.)*25.2(1.14)*359.(-29.)*4.34(-2.2) > > 23-FEB-2005 0320 CW2539 *1023.(-0.2)* 30(-10.)*24.9(1.43)*326.(3.81)*1.74( > 0.4) > > 23-FEB-2005 0335 CW2539 *1023.(-0.2)* > 30(-10.)*25.8(0.56)*323.(6.81)*2.61(-0.5) > > 23-FEB-2005 0345 CW2539 *1023.(-0.2)* 30(-10.)*25.2(1.14)*360.(-30.)*1.74( > 0.4) > > 23-FEB-2005 0401 CW2539 *1023.(0.22)* > 30(-12.)*25.5(-0.1)*332.(7.39)*1.74(0.38) > > 23-FEB-2005 0416 CW2539 *1023.(-0.1)* 30(-12.)*26.1(-0.6)* 0(-42.)* 0(2.12) > > 23-FEB-2005 0432 CW2539 *1024.(-0.1)* > 29(-11.)*24.8(0.65)*350.(-10.)*1.74(0.38) > > 23-FEB-2005 0447 CW2539 *1024.(-0.1)* > 28(-10.)*23.8(1.63)*315.(24.4)*1.74(0.38) > > 23-FEB-2005 0502 CW2539 *1024.( 0.1)* > 28(-10.)*23.8(1.25)*357.(-17.)*0.87(1.17) > > 23-FEB-2005 0518 CW2539 *1024.(-0.1)* > 28(-10.)*23.5(1.53)*360.(-20.)*0.87(1.17) > > 23-FEB-2005 0533 CW2539 *1024.(-0.3)* 28(-10.)*23.5(1.53)*354.(-14.)*1.74( > 0.3) > > 23-FEB-2005 0549 CW2539 *1024.(-0.6)* 28(-10.)*23.2(1.82)* 0(-41.)* 0(2.04) > > 23-FEB-2005 0604 CW2539 *1024.(0.25)* 28(-11.)*23.5(0.15)* 0(-36.)* 0(3.09) > > 23-FEB-2005 0619 CW2539 *1024.(0.05)* 27(-10.)*23.1(0.57)* 0(-36.)* 0(3.09) > > 23-FEB-2005 0635 CW2539 *1025.(-0.1)* 27(-10.)*22.8(0.85)* 0(-36.)* 0(3.09) > > 23-FEB-2005 0650 CW2539 *1025.(-0.2)* 27(-10.)*22.5(1.13)* > 13(-28.)*2.61(0.48) > > 23-FEB-2005 0700 CW2539 *1025.(-0.2)* 26(-10.)*22.7(-0.2)* 0(-28.)* 0(1.81) > > 23-FEB-2005 0716 CW2539 *1025.(-0.2)* 26(-10.)*22.4(0.11)* > 31(-37.)*0.87(0.94) > > 23-FEB-2005 0731 CW2539 *1025.(-0.3)* 26(-10.)*21.6(0.95)* 0(-28.)* 0(1.81) > > 23-FEB-2005 0747 CW2539 *1025.(-0.3)* 25(-9.3)*20.6(1.93)* 0(-28.)* 0(1.81) > > 23-FEB-2005 0802 CW2539 *1025.(0.21)* > 25(-12.)*20.6(0.17)*360.(-26.)*0.87(0.67) > > 23-FEB-2005 0817 CW2539 *1025.(0.01)* 25(-12.)*20.9(-0.1)* 0(-48.)* 0(1.54) > > 23-FEB-2005 0833 CW2539 *1025.(0.19)* 24(-11.)*19.9(0.87)* 0(-48.)* 0(1.54) > > 23-FEB-2005 0848 CW2539 *1025.( -0)* 24(-11.)*19.9(0.87)* 0(-48.)* 0(1.54) > > 23-FEB-2005 0904 CW2539 *1025.(-0.1)* 24(-13.)*20.2(-0.5)* 0(-71.)* 0(1.08) > > 23-FEB-2005 0919 CW2539 *1025.( -0)* 24(-13.)*20.4(-0.8)* 0(-71.)* 0(1.08) > > 23-FEB-2005 0935 CW2539 *1025.(0.09)* 24(-13.)*20.2(-0.5)* 0(-71.)* 0(1.08) > > 23-FEB-2005 0950 CW2539 *1025.(-0.1)* 23(-12.)*18.9(0.74)* 0(-71.)* 0(1.08) > > 23-FEB-2005 1001 CW2539 *1026.(0.03)* 22(-12.)*18.2(-0.3)* 0(-86.)* 0(1.42) > > 23-FEB-2005 1016 CW2539 *1026.(-0.4)* 21(-11.)*17.5(0.43)* 0(-86.)* 0(1.42) > > 23-FEB-2005 1032 CW2539 *1026.(-0.5)* > 21(-11.)*17.8(0.16)*357.(-62.)*0.87(0.55) > > 23-FEB-2005 1047 CW2539 *1026.(-0.8)* 20(-10.)*16.8(1.14)* 0(-86.)* 0(1.42) > > 23-FEB-2005 1103 CW2539 *1026.(-0.1)* > 19(-12.)*15.8(0.82)*357.(39.7)*0.87(-0.2) > > 23-FEB-2005 1118 CW2539 *1027.(-0.3)* 20(-13.)* > 17(-0.4)*333.(63.7)*0.87(-0.2) > > 23-FEB-2005 1134 CW2539 *1027.(-0.4)* > 20(-11.)*17.3(-0.7)*315.(81.7)*0.87(-0.2) > > 23-FEB-2005 1149 CW2539 *1027.(-0.7)* 20(-13.)*17.3(-0.7)* 0(-48.)* 0(0.64) > > 23-FEB-2005 1205 CW2539 *1027.(-0.3)* 19(-11.)* 16(0.55)* 0(-48.)* 0(0.64) > > 23-FEB-2005 1220 CW2539 *1027.(-0.3)* 19(-11.)* > 16(0.55)*315.(17.9)*0.87(-0.2) > > 23-FEB-2005 1230 CW2539 *1027.(-0.3)* 18(-12.)*14.8(1.79)* 0(-48.)* 0(0.64) > > 23-FEB-2005 1246 CW2539 *1027.(-0.6)* 18(-12.)*14.8(1.79)* 0(-48.)* 0(0.64) > > 23-FEB-2005 1302 CW2539 *1027.(-0.4)* 18(-12.)*15.1(-0.1)* 0(-121.)* 0(0.11) > > 23-FEB-2005 1317 CW2539 *1027.(-0.4)* > 19(-13.)*16.6(-1.6)*270.(-9.8)*1.74(-1.6) > > 23-FEB-2005 1333 CW2539 *1028.(-0.7)* > 19(-13.)*16.3(-1.3)*265.(-4.8)*2.61(-2.5) > > 23-FEB-2005 1348 CW2539 *1027.(-0.5)* > 19(-13.)*16.6(-1.6)*299.(-38.)*0.87(-0.8) > > 23-FEB-2005 1404 CW2539 *1027.(-0.5)* 19(-9.2)*16.3(2.54)* 0(-33.)* 0(0.68) > > 23-FEB-2005 1420 CW2539 *1027.(-0.4)* 20(-10.)* 17(1.81)* 0(-33.)* 0(0.68) > > 23-FEB-2005 1433 CW2539 *1027.(-0.3)* 21(-11.)* 18(0.82)* 0(-33.)* 0(0.68) > > 23-FEB-2005 1448 CW2539 *1027.(-0.3)* 25(-14.)*21.1(-2.3)* 0(-33.)* 0(0.68) > > 23-FEB-2005 1503 CW2539 *1027.(-0.3)* > 28(-11.)*21.7(-2.1)*319.(14.7)*0.87(0.37) > > 23-FEB-2005 1518 CW2539 *1027.(-0.3)* > 29(-12.)*20.5(-0.8)*298.(35.7)*0.87(0.37) > > 23-FEB-2005 1533 CW2539 *1027.(-0.6)* > 27(-12.)*19.2(0.44)*281.(52.7)*0.87(0.37) > > 23-FEB-2005 1548 CW2539 *1027.(-0.2)* > 29(-14.)*20.8(-1.2)*320.(13.7)*0.87(0.37) > > 23-FEB-2005 1603 CW2539 *1027.( -0)* 32(-12.)*23.3(-3.8)* 0(-19.)* 0(0.58) > > 23-FEB-2005 1618 CW2539 *1026.(0.26)* 36(-17.)* 21(-1.5)* 0(-19.)* 0(0.58) > > 23-FEB-2005 1633 CW2539 *1026.(0.36)* 37(-18.)*20.1(-0.6)*322.(40.1)*2.61( > -2) > > 23-FEB-2005 1648 CW2539 *1026.(-0.2)* 39(-18.)*20.5(-2.1)* 0(-80.)* 0(0.68) > > 23-FEB-2005 1703 CW2539 *1026.(0.08)* 38(-17.)*19.6(-1.2)* 0(-80.)* 0(0.68) > > 23-FEB-2005 1718 CW2539 *1026.(0.08)* > 38(-17.)*20.6(-2.1)*359.(-57.)*4.34(-3.7) > > 23-FEB-2005 1733 CW2539 *1026.(0.28)* > 39(-18.)*19.5(-1.1)*309.(-7.5)*2.61(-1.9) > > 23-FEB-2005 1748 CW2539 *1026.(0.38)* > 34(-13.)*15.9(2.51)*253.(48.5)*2.61(-1.9) > > 23-FEB-2005 1803 CW2539 *1026.(-0.2)* > 34(-12.)*19.1(-2.4)*248.(41.7)*4.34(-2.5) > > 23-FEB-2005 1818 CW2539 *1026.(-0.2)* > 32(-10.)*15.9(0.77)*253.(36.7)*2.61(-0.8) > > 23-FEB-2005 1833 CW2539 *1025.( -0)* > 31(-9.7)*17.2(-0.5)*246.(43.7)*0.87(0.99) > > 23-FEB-2005 1848 CW2539 *1025.( 0.2)* 32(-10.)*18.5(-1.8)* 0(-92.)* 0(1.86) > > 23-FEB-2005 1903 CW2539 *1025.(-0.1)* > 34(-13.)*17.3(-1.4)*346.(-44.)*2.61(-0.8) > > 23-FEB-2005 1918 CW2539 *1025.( -0)* > 32(-12.)*18.5(-2.6)*344.(-42.)*2.61(-0.8) > > 23-FEB-2005 1933 CW2539 *1025.(-0.2)* > 33(-13.)*18.6(-2.7)*315.(-13.)*4.34(-2.6) > > 23-FEB-2005 1948 CW2539 *1025.(-0.1)* > 32(-12.)*18.1(-2.1)*350.(-48.)*1.74(0.02) > > 23-FEB-2005 2003 CW2539 *1025.(-0.3)* 32(-12.)*18.1(-2.2)* 0(-71.)* 0(1.69) > > 23-FEB-2005 2018 CW2539 *1025.(-0.1)* 31(-11.)*14.6(1.33)* 0(-71.)* 0(1.69) > > 23-FEB-2005 2033 CW2539 *1025.(-0.1)* 31(-11.)*16.8(-0.8)*318.(-7.2)*1.74( > -0) > > 23-FEB-2005 2048 CW2539 *1024.(0.08)* 32(-12.)*16.4(-0.5)* 0(-71.)* 0(1.69) > > 23-FEB-2005 2103 CW2539 *1024.(-0.4)* 32(-12.)*17.3(-0.3)*342.( > 24)*0.87(0.44) > > 23-FEB-2005 2118 CW2539 *1025.(-0.6)* 32(-12.)*20.9(-3.9)* 0(-15.)* 0(1.31) > > 23-FEB-2005 2133 CW2539 *1024.(-0.4)* 32(-12.)*20.5(-3.5)* > 28(-22.)*0.87(0.44) > > 23-FEB-2005 2148 CW2539 *1024.(-0.3)* 31(-11.)*17.6(-0.6)* 0(-15.)* 0(1.31) > > 23-FEB-2005 2203 CW2539 *1024.(-0.1)* 30(-10.)*18.2(-1.4)* > 56(36.5)*0.87(-0.3) > > 23-FEB-2005 2218 CW2539 *1025.(-0.5)* 28(-8.9)*17.8( > -1)*143.(-50.)*5.21(-4.7) > > 23-FEB-2005 2233 CW2539 *1025.(-0.6)* > 27(-7.9)*18.5(-1.8)*145.(-52.)*3.48(-2.9) > > 23-FEB-2005 2248 CW2539 *1025.(-1.1)* > 27(-7.9)*19.2(-2.4)*127.(-34.)*0.87(-0.3) > > 23-FEB-2005 2303 CW2539 *1025.(-0.7)* > 26(-7.3)*19.8(-1.8)*113.(-10.)*1.74(-0.1) > > 23-FEB-2005 2318 CW2539 *1025.(-0.7)* 26(-7.4)*19.8(-1.8)* 0(81.2)* 0(1.63) > > 23-FEB-2005 2333 CW2539 *1025.(-0.7)* > 26(-7.4)*19.5(-1.5)*145.(-42.)*1.74(-0.1) > > 23-FEB-2005 2348 CW2539 *1025.(-1.1)* 26(-7.4)*19.8(-1.8)* 0(81.2)* 0(1.63) > > 23-FEB-2005 Errs CW2539 * 0/97 * 8/97 * 0/97 * 0/97 * 0/97 > > 23-FEB-2005 Smry CW2539 > *-0.2(0.32)*-11.(2.11)*-0.2(1.43)*-21.(40.8)*0.48(1.44) > > > > I originally determined my elevation using a handheld GPS to be 900' MSL. > Over the past week I have determined that the elevation is actually 870' > MSL. I have correct the elevation in the hardware and software and now the > barometer readings seem to be within acceptable limits. > > I am know focusing my attention on the temperature readings. My readings, > according to the graphs and reports, seem to indicate that the Potential > Temperature reading is consistently 10 to 12 degrees high. I know my > temperature readings are occasionally high due to the placement of the > sensor array (I plan to move it to another location this spring), but when I > look at other stations in my area (airports - KPTK, K7D2, KDET, and KMTC) my > readings seem to be off only 3 to 4 degrees. In analyzing the Weather > Quality report, if I am interpreting it correctly, it indicates that I only > have 8 errors out of 97 readings. > > Can anyone with experience in this matter please tell me what I am doing > wrong/right? > > Thanks for your help, > > -Palen CW2539 > > From Russell.B.Chadwick at noaa.gov Thu Feb 24 12:17:02 2005 From: Russell.B.Chadwick at noaa.gov (Russ Chadwick) Date: Thu Feb 24 12:17:07 2005 Subject: [wxqc] Another QC Report Question Message-ID: Mike, Palen, I've made the C2539 elevation change to the CWOP database and it will show up here, http://www.wxqa.com/states/MI.html later today, on MesoWest overnight, and in the MADIS QC next Wednesday afternoon. Russ -----Original Message----- From: Michael F Barth [mailto:Michael.F.Barth@noaa.gov] Sent: Thursday, February 24, 2005 9:41 AM To: oldrhinebeck@comcast.net; Discussion of data quality issues Cc: Russ Chadwick Subject: Re: [wxqc] Another QC Report Question Palen, I'm amazed your temperature QC is as good as it is (10% failure) given that a) the QC is done on potential temperature, and elevation is used in the conversion, and b) our station table has you listed at 900 meters, when it should have been 900 ft! Russ: He's now measured his elevation to be 870 ft, so please update the station table to 265.176 meters. Thanks, Mike On Thu, 24 Feb 2005, Palen M. Elder wrote: > Hi to all! > > I have been a member since September 2004 and am just now trying to make > sure the data that I am submitting is accurate (better late than never). I > have the following hardware and software: > > Davis Wireless Vantage PRO > Virtual Weather Station - Internet Edition v12.07 p31 > VWSaprs v1.9.4.0 > > I have been reviewing the graphs for my station at : > http://pond1.gladstonefamily.net:8080/cgi-bin/wxqchart.pl?site=C2539 over > the past week along with the Weather Quality reports that have been e-mailed > to me on a daily basis, an example of which follows: > > DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF > > * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) > > 22-FEB-2005 2345 CW2539 *1020.(0.64)* 31(-11.)*25.9(1.36)*311.(18.2)*3.48( > 0.3) > > 23-FEB-2005 0001 CW2539 *1020.(0.29)* > 31(-11.)*26.2(1.07)*336.(-6.8)*1.74(2.04) > > 23-FEB-2005 0016 CW2539 *1021.(-0.2)* > 30(-10.)*25.8(1.47)*349.(-19.)*2.61(1.17) > > 23-FEB-2005 0031 CW2539 *1021.(-0.7)* 30(-10.)*25.8(1.47)*337.(-7.8)*0.87( > 2.9) > > 23-FEB-2005 0047 CW2539 *1021.(-0.7)* 30(-10.)*26.6(0.62)* 0(-52.)* 0(3.77) > > 23-FEB-2005 0102 CW2539 *1021.(0.27)* 31(-11.)* 27( > -0)*312.(20.1)*0.87(1.57) > > 23-FEB-2005 0117 CW2539 *1022.(0.17)* > 31(-11.)*27.6(-0.6)*343.(-10.)*0.87(1.57) > > 23-FEB-2005 0133 CW2539 *1022.( -0)* 31(-11.)*26.7(0.25)*313.(19.1)*1.74( > 0.7) > > 23-FEB-2005 0148 CW2539 *1022.( -0)* > 31(-11.)*27.6(-0.6)*342.(-9.9)*2.61(-0.2) > > 23-FEB-2005 0203 CW2539 *1022.(0.24)* 31(-11.)* > 27(0.25)*344.(-24.)*4.34(-0.8) > > 23-FEB-2005 0219 CW2539 *1022.(0.04)* 31(-11.)* > 27(0.25)*340.(-20.)*2.61(0.93) > > 23-FEB-2005 0234 CW2539 *1022.(-0.2)* 31(-11.)*26.2(1.12)*360.(-40.)*1.74( > 1.8) > > 23-FEB-2005 0249 CW2539 *1023.(0.16)* 30(-10.)*25.5(0.84)* > 7(-37.)*0.87(1.27) > > 23-FEB-2005 0304 CW2539 *1023.(0.04)* > 30(-10.)*25.2(1.14)*359.(-29.)*4.34(-2.2) > > 23-FEB-2005 0320 CW2539 *1023.(-0.2)* 30(-10.)*24.9(1.43)*326.(3.81)*1.74( > 0.4) > > 23-FEB-2005 0335 CW2539 *1023.(-0.2)* > 30(-10.)*25.8(0.56)*323.(6.81)*2.61(-0.5) > > 23-FEB-2005 0345 CW2539 *1023.(-0.2)* 30(-10.)*25.2(1.14)*360.(-30.)*1.74( > 0.4) > > 23-FEB-2005 0401 CW2539 *1023.(0.22)* > 30(-12.)*25.5(-0.1)*332.(7.39)*1.74(0.38) > > 23-FEB-2005 0416 CW2539 *1023.(-0.1)* 30(-12.)*26.1(-0.6)* 0(-42.)* 0(2.12) > > 23-FEB-2005 0432 CW2539 *1024.(-0.1)* > 29(-11.)*24.8(0.65)*350.(-10.)*1.74(0.38) > > 23-FEB-2005 0447 CW2539 *1024.(-0.1)* > 28(-10.)*23.8(1.63)*315.(24.4)*1.74(0.38) > > 23-FEB-2005 0502 CW2539 *1024.( 0.1)* > 28(-10.)*23.8(1.25)*357.(-17.)*0.87(1.17) > > 23-FEB-2005 0518 CW2539 *1024.(-0.1)* > 28(-10.)*23.5(1.53)*360.(-20.)*0.87(1.17) > > 23-FEB-2005 0533 CW2539 *1024.(-0.3)* 28(-10.)*23.5(1.53)*354.(-14.)*1.74( > 0.3) > > 23-FEB-2005 0549 CW2539 *1024.(-0.6)* 28(-10.)*23.2(1.82)* 0(-41.)* 0(2.04) > > 23-FEB-2005 0604 CW2539 *1024.(0.25)* 28(-11.)*23.5(0.15)* 0(-36.)* 0(3.09) > > 23-FEB-2005 0619 CW2539 *1024.(0.05)* 27(-10.)*23.1(0.57)* 0(-36.)* 0(3.09) > > 23-FEB-2005 0635 CW2539 *1025.(-0.1)* 27(-10.)*22.8(0.85)* 0(-36.)* 0(3.09) > > 23-FEB-2005 0650 CW2539 *1025.(-0.2)* 27(-10.)*22.5(1.13)* > 13(-28.)*2.61(0.48) > > 23-FEB-2005 0700 CW2539 *1025.(-0.2)* 26(-10.)*22.7(-0.2)* 0(-28.)* 0(1.81) > > 23-FEB-2005 0716 CW2539 *1025.(-0.2)* 26(-10.)*22.4(0.11)* > 31(-37.)*0.87(0.94) > > 23-FEB-2005 0731 CW2539 *1025.(-0.3)* 26(-10.)*21.6(0.95)* 0(-28.)* 0(1.81) > > 23-FEB-2005 0747 CW2539 *1025.(-0.3)* 25(-9.3)*20.6(1.93)* 0(-28.)* 0(1.81) > > 23-FEB-2005 0802 CW2539 *1025.(0.21)* > 25(-12.)*20.6(0.17)*360.(-26.)*0.87(0.67) > > 23-FEB-2005 0817 CW2539 *1025.(0.01)* 25(-12.)*20.9(-0.1)* 0(-48.)* 0(1.54) > > 23-FEB-2005 0833 CW2539 *1025.(0.19)* 24(-11.)*19.9(0.87)* 0(-48.)* 0(1.54) > > 23-FEB-2005 0848 CW2539 *1025.( -0)* 24(-11.)*19.9(0.87)* 0(-48.)* 0(1.54) > > 23-FEB-2005 0904 CW2539 *1025.(-0.1)* 24(-13.)*20.2(-0.5)* 0(-71.)* 0(1.08) > > 23-FEB-2005 0919 CW2539 *1025.( -0)* 24(-13.)*20.4(-0.8)* 0(-71.)* 0(1.08) > > 23-FEB-2005 0935 CW2539 *1025.(0.09)* 24(-13.)*20.2(-0.5)* 0(-71.)* 0(1.08) > > 23-FEB-2005 0950 CW2539 *1025.(-0.1)* 23(-12.)*18.9(0.74)* 0(-71.)* 0(1.08) > > 23-FEB-2005 1001 CW2539 *1026.(0.03)* 22(-12.)*18.2(-0.3)* 0(-86.)* 0(1.42) > > 23-FEB-2005 1016 CW2539 *1026.(-0.4)* 21(-11.)*17.5(0.43)* 0(-86.)* 0(1.42) > > 23-FEB-2005 1032 CW2539 *1026.(-0.5)* > 21(-11.)*17.8(0.16)*357.(-62.)*0.87(0.55) > > 23-FEB-2005 1047 CW2539 *1026.(-0.8)* 20(-10.)*16.8(1.14)* 0(-86.)* 0(1.42) > > 23-FEB-2005 1103 CW2539 *1026.(-0.1)* > 19(-12.)*15.8(0.82)*357.(39.7)*0.87(-0.2) > > 23-FEB-2005 1118 CW2539 *1027.(-0.3)* 20(-13.)* > 17(-0.4)*333.(63.7)*0.87(-0.2) > > 23-FEB-2005 1134 CW2539 *1027.(-0.4)* > 20(-11.)*17.3(-0.7)*315.(81.7)*0.87(-0.2) > > 23-FEB-2005 1149 CW2539 *1027.(-0.7)* 20(-13.)*17.3(-0.7)* 0(-48.)* 0(0.64) > > 23-FEB-2005 1205 CW2539 *1027.(-0.3)* 19(-11.)* 16(0.55)* 0(-48.)* 0(0.64) > > 23-FEB-2005 1220 CW2539 *1027.(-0.3)* 19(-11.)* > 16(0.55)*315.(17.9)*0.87(-0.2) > > 23-FEB-2005 1230 CW2539 *1027.(-0.3)* 18(-12.)*14.8(1.79)* 0(-48.)* 0(0.64) > > 23-FEB-2005 1246 CW2539 *1027.(-0.6)* 18(-12.)*14.8(1.79)* 0(-48.)* 0(0.64) > > 23-FEB-2005 1302 CW2539 *1027.(-0.4)* 18(-12.)*15.1(-0.1)* 0(-121.)* 0(0.11) > > 23-FEB-2005 1317 CW2539 *1027.(-0.4)* > 19(-13.)*16.6(-1.6)*270.(-9.8)*1.74(-1.6) > > 23-FEB-2005 1333 CW2539 *1028.(-0.7)* > 19(-13.)*16.3(-1.3)*265.(-4.8)*2.61(-2.5) > > 23-FEB-2005 1348 CW2539 *1027.(-0.5)* > 19(-13.)*16.6(-1.6)*299.(-38.)*0.87(-0.8) > > 23-FEB-2005 1404 CW2539 *1027.(-0.5)* 19(-9.2)*16.3(2.54)* 0(-33.)* 0(0.68) > > 23-FEB-2005 1420 CW2539 *1027.(-0.4)* 20(-10.)* 17(1.81)* 0(-33.)* 0(0.68) > > 23-FEB-2005 1433 CW2539 *1027.(-0.3)* 21(-11.)* 18(0.82)* 0(-33.)* 0(0.68) > > 23-FEB-2005 1448 CW2539 *1027.(-0.3)* 25(-14.)*21.1(-2.3)* 0(-33.)* 0(0.68) > > 23-FEB-2005 1503 CW2539 *1027.(-0.3)* > 28(-11.)*21.7(-2.1)*319.(14.7)*0.87(0.37) > > 23-FEB-2005 1518 CW2539 *1027.(-0.3)* > 29(-12.)*20.5(-0.8)*298.(35.7)*0.87(0.37) > > 23-FEB-2005 1533 CW2539 *1027.(-0.6)* > 27(-12.)*19.2(0.44)*281.(52.7)*0.87(0.37) > > 23-FEB-2005 1548 CW2539 *1027.(-0.2)* > 29(-14.)*20.8(-1.2)*320.(13.7)*0.87(0.37) > > 23-FEB-2005 1603 CW2539 *1027.( -0)* 32(-12.)*23.3(-3.8)* 0(-19.)* 0(0.58) > > 23-FEB-2005 1618 CW2539 *1026.(0.26)* 36(-17.)* 21(-1.5)* 0(-19.)* 0(0.58) > > 23-FEB-2005 1633 CW2539 *1026.(0.36)* 37(-18.)*20.1(-0.6)*322.(40.1)*2.61( > -2) > > 23-FEB-2005 1648 CW2539 *1026.(-0.2)* 39(-18.)*20.5(-2.1)* 0(-80.)* 0(0.68) > > 23-FEB-2005 1703 CW2539 *1026.(0.08)* 38(-17.)*19.6(-1.2)* 0(-80.)* 0(0.68) > > 23-FEB-2005 1718 CW2539 *1026.(0.08)* > 38(-17.)*20.6(-2.1)*359.(-57.)*4.34(-3.7) > > 23-FEB-2005 1733 CW2539 *1026.(0.28)* > 39(-18.)*19.5(-1.1)*309.(-7.5)*2.61(-1.9) > > 23-FEB-2005 1748 CW2539 *1026.(0.38)* > 34(-13.)*15.9(2.51)*253.(48.5)*2.61(-1.9) > > 23-FEB-2005 1803 CW2539 *1026.(-0.2)* > 34(-12.)*19.1(-2.4)*248.(41.7)*4.34(-2.5) > > 23-FEB-2005 1818 CW2539 *1026.(-0.2)* > 32(-10.)*15.9(0.77)*253.(36.7)*2.61(-0.8) > > 23-FEB-2005 1833 CW2539 *1025.( -0)* > 31(-9.7)*17.2(-0.5)*246.(43.7)*0.87(0.99) > > 23-FEB-2005 1848 CW2539 *1025.( 0.2)* 32(-10.)*18.5(-1.8)* 0(-92.)* 0(1.86) > > 23-FEB-2005 1903 CW2539 *1025.(-0.1)* > 34(-13.)*17.3(-1.4)*346.(-44.)*2.61(-0.8) > > 23-FEB-2005 1918 CW2539 *1025.( -0)* > 32(-12.)*18.5(-2.6)*344.(-42.)*2.61(-0.8) > > 23-FEB-2005 1933 CW2539 *1025.(-0.2)* > 33(-13.)*18.6(-2.7)*315.(-13.)*4.34(-2.6) > > 23-FEB-2005 1948 CW2539 *1025.(-0.1)* > 32(-12.)*18.1(-2.1)*350.(-48.)*1.74(0.02) > > 23-FEB-2005 2003 CW2539 *1025.(-0.3)* 32(-12.)*18.1(-2.2)* 0(-71.)* 0(1.69) > > 23-FEB-2005 2018 CW2539 *1025.(-0.1)* 31(-11.)*14.6(1.33)* 0(-71.)* 0(1.69) > > 23-FEB-2005 2033 CW2539 *1025.(-0.1)* 31(-11.)*16.8(-0.8)*318.(-7.2)*1.74( > -0) > > 23-FEB-2005 2048 CW2539 *1024.(0.08)* 32(-12.)*16.4(-0.5)* 0(-71.)* 0(1.69) > > 23-FEB-2005 2103 CW2539 *1024.(-0.4)* 32(-12.)*17.3(-0.3)*342.( > 24)*0.87(0.44) > > 23-FEB-2005 2118 CW2539 *1025.(-0.6)* 32(-12.)*20.9(-3.9)* 0(-15.)* 0(1.31) > > 23-FEB-2005 2133 CW2539 *1024.(-0.4)* 32(-12.)*20.5(-3.5)* > 28(-22.)*0.87(0.44) > > 23-FEB-2005 2148 CW2539 *1024.(-0.3)* 31(-11.)*17.6(-0.6)* 0(-15.)* 0(1.31) > > 23-FEB-2005 2203 CW2539 *1024.(-0.1)* 30(-10.)*18.2(-1.4)* > 56(36.5)*0.87(-0.3) > > 23-FEB-2005 2218 CW2539 *1025.(-0.5)* 28(-8.9)*17.8( > -1)*143.(-50.)*5.21(-4.7) > > 23-FEB-2005 2233 CW2539 *1025.(-0.6)* > 27(-7.9)*18.5(-1.8)*145.(-52.)*3.48(-2.9) > > 23-FEB-2005 2248 CW2539 *1025.(-1.1)* > 27(-7.9)*19.2(-2.4)*127.(-34.)*0.87(-0.3) > > 23-FEB-2005 2303 CW2539 *1025.(-0.7)* > 26(-7.3)*19.8(-1.8)*113.(-10.)*1.74(-0.1) > > 23-FEB-2005 2318 CW2539 *1025.(-0.7)* 26(-7.4)*19.8(-1.8)* 0(81.2)* 0(1.63) > > 23-FEB-2005 2333 CW2539 *1025.(-0.7)* > 26(-7.4)*19.5(-1.5)*145.(-42.)*1.74(-0.1) > > 23-FEB-2005 2348 CW2539 *1025.(-1.1)* 26(-7.4)*19.8(-1.8)* 0(81.2)* 0(1.63) > > 23-FEB-2005 Errs CW2539 * 0/97 * 8/97 * 0/97 * 0/97 * 0/97 > > 23-FEB-2005 Smry CW2539 > *-0.2(0.32)*-11.(2.11)*-0.2(1.43)*-21.(40.8)*0.48(1.44) > > > > I originally determined my elevation using a handheld GPS to be 900' MSL. > Over the past week I have determined that the elevation is actually 870' > MSL. I have correct the elevation in the hardware and software and now the > barometer readings seem to be within acceptable limits. > > I am know focusing my attention on the temperature readings. My readings, > according to the graphs and reports, seem to indicate that the Potential > Temperature reading is consistently 10 to 12 degrees high. I know my > temperature readings are occasionally high due to the placement of the > sensor array (I plan to move it to another location this spring), but when I > look at other stations in my area (airports - KPTK, K7D2, KDET, and KMTC) my > readings seem to be off only 3 to 4 degrees. In analyzing the Weather > Quality report, if I am interpreting it correctly, it indicates that I only > have 8 errors out of 97 readings. > > Can anyone with experience in this matter please tell me what I am doing > wrong/right? > > Thanks for your help, > > -Palen CW2539 > > From James.Dudley at noaa.gov Thu Feb 24 17:58:51 2005 From: James.Dudley at noaa.gov (James Dudley) Date: Thu Feb 24 17:51:07 2005 Subject: [wxqc] Another QC Report Question Message-ID: <291cbf2933f9.2933f9291cbf@noaa.gov> Russ, On this subject, it appears that CW2745 in Reedley Ca has the elevation incorrect. It is listed at 1155 feet, when actually Reedley is around 360 feet or so in elevation. Could this be a meter to feet problem? Anyway, keep up the good work on the CWOP program. Thanks, Jim Dudley CW2553 National Weather Service Hanford CA. From sam at wa4phy.net Thu Feb 24 17:57:56 2005 From: sam at wa4phy.net (Sam Drinkard) Date: Thu Feb 24 17:57:59 2005 Subject: [wxqc] Rainfall calibration revisited Message-ID: <421E5BF4.50109@wa4phy.net> After seeing the difference between the 8" SRG and the Davis rain collector from last night and today's rain, I think perhaps it's time to make some tweaks to it. The SRG measured 0.96" total, and the Davis recorded 0.78", making a 0.18" difference. That to me is a pretty significant amount. Now, my question is, has anyone else done any tweaking of the calibration of the gauge itself, or via the console on the WM-II ? Supposedly, there is an adjustment of up to 2% for each side of the tipping bucket. I don't recall seeing it, but then again, I was not looking for it either. Before I go out and change things, just curious of anybody has any comments, pro or con. The console changes would be OK, but if the thing looses power, it defaults back to the std. calibration, which is why I'd rather make it at the gauge itself. Sam -- Snowman From Russell.B.Chadwick at noaa.gov Fri Feb 25 14:41:39 2005 From: Russell.B.Chadwick at noaa.gov (Russ Chadwick) Date: Fri Feb 25 14:41:46 2005 Subject: [wxqc] Another QC Report Question Message-ID: Hi Jim, Yes, the elevation for CW2745 was in error by about factor 3 too high. Thanks for finding this. I've fixed it in the database. A lot of US people enter elevation in feet even though the instructions on the sign-up page clearly indicate meters. We try to find and correct these, but in some areas, it's more difficult than in others. If you notice any more where the elevation appears to be wrong, let me know. Russ -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net] On Behalf Of James Dudley Sent: Thursday, February 24, 2005 3:59 PM To: Discussion of data quality issues Subject: Re: RE: [wxqc] Another QC Report Question Russ, On this subject, it appears that CW2745 in Reedley Ca has the elevation incorrect. It is listed at 1155 feet, when actually Reedley is around 360 feet or so in elevation. Could this be a meter to feet problem? Anyway, keep up the good work on the CWOP program. Thanks, Jim Dudley CW2553 National Weather Service Hanford CA. _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From alan at batie.org Sun Feb 27 16:47:06 2005 From: alan at batie.org (Alan Batie) Date: Sun Feb 27 16:51:59 2005 Subject: [wxqc] Another QC Report Question In-Reply-To: References: Message-ID: <42223FDA.2060909@batie.org> Russ Chadwick wrote: > A lot of US people enter elevation in feet even though the instructions > on the sign-up page clearly indicate meters. We try to find and correct > these, but in some areas, it's more difficult than in others. If you > notice any more where the elevation appears to be wrong, let me know. Ooops, apparently I misread it also: CW2408 is 197 ft, not m. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3196 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050227/5db5c2b6/smime.bin From alan at batie.org Tue Feb 1 01:11:22 2005 From: alan at batie.org (Alan Batie) Date: Mon, 31 Jan 2005 22:11:22 -0800 Subject: [wxqc] Sensor mounting Message-ID: <41FF1D8A.4070801@batie.org> I've just put up pictures of my sensor mounting on my weather page (http://www.rdrop.com/mrtg/weather.html down at the bottom), and am open to suggestions for improvement, though that mounting is unlikely to change. A couple of things I note is that although there's no fans in the attic, it's probably not a good idea that the vent is right under the sensors, and the rain bucket shouldn't be under the anemometer arm, though I doubt that's really affecting it much. The qc graph shows my temperature being slightly high, though it could be a local difference, being where it is seems suspect. I'm not sure I had any real alternatives though: there are some pictures of the backyard at http://alan.batie.org/backyard/ (ignore the grand plans ;-) ). Phil also said the windspeed was high and the report shows lots of errors, and I'm not quite sure how it can figure that out, as variable as wind is. Given the way things are situated, I would expect the wind to report low, and I generally don't see near the wind the tv weather reports. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3196 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050131/fc3f2ed3/attachment.bin From dshelms at comcast.net Tue Feb 1 07:04:27 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Tue, 1 Feb 2005 07:04:27 -0500 Subject: [wxqc] Sensor mounting In-Reply-To: <41FF1D8A.4070801@batie.org> Message-ID: Hi Alan, The anemometer is OK (may get some roof wind acceleration though as the wind is defkewcted up the roof line). Rooftop precip gauges are very problematic as the are in a high wind environment which causes significant rainfall under catchment as the rain is deflected over much of the gauge. The temp/rh gauge should be over the grass as roof materials will cause sampling problems. If possible, I'd remote keep the anemometer on the roof as is, but place the precip and temp/rh gauge on a free standing post about 6 feet inside the right hedge line in this picture: http://alan.batie.org/backyard/image002.htm The temp/rh at 5 feet AGL and the precip gauge on the same post, but on a horizontal bracket 1-2 feet away from the post and any possible splashing or shadowing from the temp/rh sensor. Hope this helps, Dave -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Alan Batie Sent: Tuesday, February 01, 2005 1:11 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Sensor mounting I've just put up pictures of my sensor mounting on my weather page (http://www.rdrop.com/mrtg/weather.html down at the bottom), and am open to suggestions for improvement, though that mounting is unlikely to change. A couple of things I note is that although there's no fans in the attic, it's probably not a good idea that the vent is right under the sensors, and the rain bucket shouldn't be under the anemometer arm, though I doubt that's really affecting it much. The qc graph shows my temperature being slightly high, though it could be a local difference, being where it is seems suspect. I'm not sure I had any real alternatives though: there are some pictures of the backyard at http://alan.batie.org/backyard/ (ignore the grand plans ;-) ). Phil also said the windspeed was high and the report shows lots of errors, and I'm not quite sure how it can figure that out, as variable as wind is. Given the way things are situated, I would expect the wind to report low, and I generally don't see near the wind the tv weather reports. From alan at batie.org Tue Feb 1 12:29:00 2005 From: alan at batie.org (Alan Batie) Date: Tue, 01 Feb 2005 09:29:00 -0800 Subject: [wxqc] Sensor mounting In-Reply-To: References: Message-ID: <41FFBC5C.2040606@batie.org> Sandy and David Helms wrote: > If possible, I'd remote keep the anemometer on the roof as is, but place the > precip and temp/rh gauge on a free standing post about 6 feet inside the > right hedge line That's a good idea, thanks. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3196 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050201/af02e3e1/attachment.bin From chris at yipyap.com Tue Feb 1 22:41:20 2005 From: chris at yipyap.com (Chris Howard) Date: Tue, 1 Feb 2005 20:41:20 -0700 Subject: [wxqc] BP correction In-Reply-To: <20050131214721.40141@amos>; from Chris Howard on Mon, Jan 31, 2005 at 09:47:21PM -0700 References: <20050131203318.25674@amos> <41FEFCDE.9000500@gladstonefamily.net> <20050131214721.40141@amos> Message-ID: <20050201204120.20488@amos> > > > Hmm, my goofball calculation gives me something around > 1015 mb. The calculation you suggest gives me 1051. > My neighboring CWOP stations are reporting figures > around 1030 mb. > > Maybe my raw reading is faulty? I dug out the manual for this thing, and there is a calibration procedure to set the BP value. Now the next question is, where do I get a "raw" value in inches of mercury that I can use for calibration? (Would one of those fine fellows in Boulder like to come up to Estes Park sometime and bring a calibrated barometer?) -- Chris Howard YipYap.Com chris at yipyap.com Estes Park, Colorado USA current Estes Park weather -- http://www.yipyap.com/wscurrent.html From dshelms at comcast.net Wed Feb 2 00:08:33 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Wed, 2 Feb 2005 00:08:33 -0500 Subject: [wxqc] BP correction In-Reply-To: <20050201204120.20488@amos> Message-ID: Hi Chris, Usually, we ask folks to set their pressure directly to a nearby airport altimeter on a calm wind afternoon. Altimeter is a convenient pressure value that doesn't require precise knowledge of your elevation or the reference pressure station's elevation. Again, we want altimeter pressure (not raw pressure or MSLP pressure). But.. you need to know a raw pressure, here you go. Estes Park is way high in the mountains, so you have to account for a low "station pressure" or the raw uncorrected pressure as a great deal of the Earth's atmosphere is below you. Here's the way I might try it: 1. Find a reliable pressure: In your case, Fort Collins (KFNL) is probably the closest calibrated pressure sensor. You can call the automated ASOS recording @ 970-669-9187 or get the altimeter off the Internet: Here's the pressure from the Aviation Weather Center ADDS: http://adds.aviationweather.noaa.gov/metars/index.php?station_ids=KFNL&std_t rans=translated&chk_metars=on KFNL 020435Z AUTO 01006KT 10SM FEW060 BKN065 M01/M08 A3032 RMK AO1 -- where A3032 is the Altimeter (30.32 inches of mercury) Assuming these is no big pressure gradients/differences between your location and Ft Collins 30 miles east of you, 2. Subtract the pressure between sea level and your elevation: Since altimeter is a sea level reduced pressure, you have to subtract off the pressure between sea level and your station elevation. I'm estimating your elevation in near 7,674 feet (the elevation of your hospital heliport in Estes Park). 1 foot = 0.001 inch of mercury 7674 feet * 0.001 inch / foot = 7.674 inches of pressure needed to be subtracted from the reference pressure at Ft Collins, 30.32 inches 30.32 inches - 7.674 inches = 22.646 inches or mercury, your raw station pressure. But, station pressure is usually expressed in millibars, Conversion ratio: 1.000 mb = 0.02953 inches 22.646 inches * (1 mb / 0.02953 inches) = 766.636 mb Hope this helps, Dave CW0351 P.S. The above procedure is a modified technique used to calibrate tactical barometers in the military. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Chris Howard Sent: Tuesday, February 01, 2005 10:41 PM To: Discussion of data quality issues Subject: Re: [wxqc] BP correction > > > Hmm, my goofball calculation gives me something around > 1015 mb. The calculation you suggest gives me 1051. > My neighboring CWOP stations are reporting figures > around 1030 mb. > > Maybe my raw reading is faulty? I dug out the manual for this thing, and there is a calibration procedure to set the BP value. Now the next question is, where do I get a "raw" value in inches of mercury that I can use for calibration? (Would one of those fine fellows in Boulder like to come up to Estes Park sometime and bring a calibrated barometer?) -- Chris Howard YipYap.Com chris at yipyap.com Estes Park, Colorado USA current Estes Park weather -- http://www.yipyap.com/wscurrent.html _______________________________________________ wxqc mailing list wxqc at lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From dshelms at comcast.net Wed Feb 2 00:12:39 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Wed, 2 Feb 2005 00:12:39 -0500 Subject: [wxqc] BP correction In-Reply-To: Message-ID: redrum! -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Sandy and David Helms Sent: Wednesday, February 02, 2005 12:09 AM To: Discussion of data quality issues Subject: RE: [wxqc] BP correction Hi Chris, Usually, we ask folks to set their pressure directly to a nearby airport altimeter on a calm wind afternoon. Altimeter is a convenient pressure value that doesn't require precise knowledge of your elevation or the reference pressure station's elevation. Again, we want altimeter pressure (not raw pressure or MSLP pressure). But.. you need to know a raw pressure, here you go. Estes Park is way high in the mountains, so you have to account for a low "station pressure" or the raw uncorrected pressure as a great deal of the Earth's atmosphere is below you. Here's the way I might try it: 1. Find a reliable pressure: In your case, Fort Collins (KFNL) is probably the closest calibrated pressure sensor. You can call the automated ASOS recording @ 970-669-9187 or get the altimeter off the Internet: Here's the pressure from the Aviation Weather Center ADDS: http://adds.aviationweather.noaa.gov/metars/index.php?station_ids=KFNL&std_t rans=translated&chk_metars=on KFNL 020435Z AUTO 01006KT 10SM FEW060 BKN065 M01/M08 A3032 RMK AO1 -- where A3032 is the Altimeter (30.32 inches of mercury) Assuming these is no big pressure gradients/differences between your location and Ft Collins 30 miles east of you, 2. Subtract the pressure between sea level and your elevation: Since altimeter is a sea level reduced pressure, you have to subtract off the pressure between sea level and your station elevation. I'm estimating your elevation in near 7,674 feet (the elevation of your hospital heliport in Estes Park). 1 foot = 0.001 inch of mercury 7674 feet * 0.001 inch / foot = 7.674 inches of pressure needed to be subtracted from the reference pressure at Ft Collins, 30.32 inches 30.32 inches - 7.674 inches = 22.646 inches or mercury, your raw station pressure. But, station pressure is usually expressed in millibars, Conversion ratio: 1.000 mb = 0.02953 inches 22.646 inches * (1 mb / 0.02953 inches) = 766.636 mb Hope this helps, Dave CW0351 P.S. The above procedure is a modified technique used to calibrate tactical barometers in the military. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Chris Howard Sent: Tuesday, February 01, 2005 10:41 PM To: Discussion of data quality issues Subject: Re: [wxqc] BP correction > > > Hmm, my goofball calculation gives me something around > 1015 mb. The calculation you suggest gives me 1051. > My neighboring CWOP stations are reporting figures > around 1030 mb. > > Maybe my raw reading is faulty? I dug out the manual for this thing, and there is a calibration procedure to set the BP value. Now the next question is, where do I get a "raw" value in inches of mercury that I can use for calibration? (Would one of those fine fellows in Boulder like to come up to Estes Park sometime and bring a calibrated barometer?) -- Chris Howard YipYap.Com chris at yipyap.com Estes Park, Colorado USA current Estes Park weather -- http://www.yipyap.com/wscurrent.html _______________________________________________ wxqc mailing list wxqc at lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc _______________________________________________ wxqc mailing list wxqc at lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From chris at yipyap.com Wed Feb 2 12:18:31 2005 From: chris at yipyap.com (chris at yipyap.com) Date: Wed, 2 Feb 2005 17:18:31 -0000 Subject: [wxqc] more on BP calibration Message-ID: <200502021718.j12HIVEG005089@web156.megawebservers.com> Well I'm a little more enlightened and a little more confused. Using Phillip Gladstone's calculation for altitude correction gives me different numbers than using what I think David Helms was suggesting (0.001 inch per foot of elevation change). Comparing my station with Fort Collins, it looks to me like I'm currently somewhere between 0.69 and 0.89 high with my raw inches-of-mercury reading. Then I'm applying an altitude correction that leaves me with a reported mb figure that is somewhere around 10-20 mb low compared to the new other CW station in town. So if I calibrate my raw readings to be 0.79 lower and then use Phillip's altitude correction I would come out slightly higher than Fort Collins for reported mb figure. Is being +/- 0.1 inches of mercury considered close enough? I don't know how confident I am with the idea of comparing with Fort Collins. It's 30 miles away and on the plains at ~5000 feet. I'm in a high mountain park at ~7800 ft. But that does sound like the nearest calibrated point. Do these sensors drift over time? or you think I have been off by this much from the very beginning? (I bought the thing in 1996.) Chris Howard chris at yipyap.com From dshelms at comcast.net Wed Feb 2 14:54:39 2005 From: dshelms at comcast.net (dshelms at comcast.net) Date: Wed, 02 Feb 2005 19:54:39 +0000 Subject: [wxqc] more on BP calibration Message-ID: <020220051954.11366.42012FFF0000426100002C6622070016419C03040A089C0B@comcast.net> See comments below... Dave CW0351 > > Well I'm a little more enlightened and a little more confused. > > Using Phillip Gladstone's calculation for altitude correction > gives me different numbers than using what I think David Helms > was suggesting (0.001 inch per foot of elevation change). > --- see below on discussion of QCMS statistics. > Comparing my station with Fort Collins, it looks to me like > I'm currently somewhere between 0.69 and 0.89 high with my raw > inches-of-mercury reading. Then I'm applying an altitude > correction that leaves me with a reported mb figure that is > somewhere around 10-20 mb low compared to the new other CW > station in town. --- That CW is probably not calibrated yet (fact: at lest 25% of all CWOP stations get flagged for pressure issues, very problematic). The thing is, adjusting pressure is a rather trivial thing to do; unfortunately, people don't have enough information to make an accurate adjustment (the wrong answer is to listen to the radio). > > So if I calibrate my raw readings to be 0.79 lower and then > use Phillip's altitude correction I would come out slightly > higher than Fort Collins for reported mb figure. Is being > +/- 0.1 inches of mercury considered close enough? --- 00.03 inches or 1.0 mb of actual pressure is the target accuracy, I won't say +/- 00.10 inch is good or bad when looking at KFNL as atmospheric pressure variations may cause that difference to dramatically vary. At least it shows you are getting close. > > I don't know how confident I am with the idea of comparing > with Fort Collins. It's 30 miles away and on the plains at > ~5000 feet. I'm in a high mountain park at ~7800 ft. > But that does sound like the nearest calibrated point. --- That is what is available through the Internet anyway. Your elevation difference is similar to the Lararie (KLAR) and Cheyenne (KCYS) mountain vs. high plains situation elevation difference (I think they are 00.02 inches different today). If you have to use an airport that is more than 10 miles and a few hundred feet different elevation, do so with care. Always do your comparisons during light winds (high pressure) to minimize the pressure differences, especially when using a more distant "reference" pressure. You might try the Estes Park Medical Center's Heliport, 970-586-2317, and see if they have a calibrated altimeter for the inbound Medevacs (make sure they aren't busy!). > > Do these sensors drift over time? or you think I have > been off by this much from the very beginning? (I bought > the thing in 1996.) > --- Definitely. You should reaccomplish pressure calibration checks every 6 months or better. Hopefully, the QCMS data will give you a heads-up when things get out of whack. The problem with QCMS is it relies on your buddy station's pressures to create the "analysis" field, if the analysis includes several poorly calibrated pressures, then the analysis is not going to be very useful. That's why I say use a pressure sensor you know is professionally maintained which in most cases will be the local airport ASOS/AWOS. > Chris Howard > chris at yipyap.com > _______________________________________________ > wxqc mailing list > wxqc at lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050202/e1eafca9/attachment-0002.html From dshelms at comcast.net Wed Feb 2 15:14:23 2005 From: dshelms at comcast.net (dshelms at comcast.net) Date: Wed, 02 Feb 2005 20:14:23 +0000 Subject: [wxqc] more on BP calibration Message-ID: <020220052014.23190.4201349C000006F400005A9622007347489C03040A089C0B@comcast.net> All: I consider CWOP pressure instruments to be on the same quality and performance I used in the military, which is why I recommend using the Air Force's pressure tactical standardization procedures, as described in the following document (219 pages): Air Force Manual on (Weather) Surface Observations: http://www.e-publishing.af.mil/pubfiles/af/15/afman15-111/afman15-111.pdf Check out section 12.4.2, Standardization of Tacitical Barometers and the elevation removal correction (1 ft = 00.001 inch of mercury). Don't get too tripped up by the references to specific pressure instruments, just try and get the methodology they are describing. -------------- Original message -------------- See comments below... Dave CW0351 > > Well I'm a little more enlightened and a little more confused. > > Using Phillip Gladstone's calculation for altitude correction > gives me different numbers than using what I think David Helms > was suggesting (0.001 inch per foot of elevation change). > --- see below on discussion of QCMS statistics. > Comparing my station with Fort Collins, it looks to me like > I'm currently somewhere between 0.69 and 0.89 high with my raw > inches-of-mercury reading. Then I'm applying an altitude > correction that leaves me with a reported mb figure that is > somewhere around 10-20 mb low compared to the new other CW > station in town. --- That CW is probably not calibrated yet (fact: at lest 25% of all CWOP stations get flagged for pressure issues, very problematic). The thing is, adjusting pressure is a rather trivial thing to do; unfortunately, people don't have enough information to make an accurate adjustment (the wrong answer is to listen to the radio). > > So if I calibrate my raw readings to be 0.79 lower and then > use Phillip's altitude correction I would come out slightly > higher than Fort Collins for reported mb figure. Is being > +/- 0.1 inches of mercury considered close enough? --- 00.03 inches or 1.0 mb of actual pressure is the target accuracy, I won't say +/- 00.10 inch is good or bad when looking at KFNL as atmospheric pressure variations may cause that difference to dramatically vary. At least it shows you are getting close. > > I don't know how confident I am with the idea of comparing > with Fort Collins. It's 30 miles away and on the plains at > ~5000 feet. I'm in a high mountain park at ~7800 ft. > But that does sound like the nearest calibrated point. --- That is what is available through the Internet anyway. Your elevation difference is similar to the Lararie (KLAR) and Cheyenne (KCYS) mountain vs. high plains situation elevation difference (I think they are 00.02 inches different today). If you have to use an airport that is more than 10 miles and a few hundred feet different elevation, do so with care. Always do your comparisons during light winds (high pressure) to minimize the pressure differences, especially when using a more distant "reference" pressure. You might try the Estes Park Medical Center's Heliport, 970-586-2317, and see if they have a calibrated altimeter for the inbound Medevacs (make sure they aren't busy!). > > Do these sensors drift over time? or you think I have > been off by this much from the very beginning? (I bought > the thing in 1996.) > --- Definitely. You should reaccomplish pressure calibration checks every 6 months or better. Hopefully, the QCMS data will give you a heads-up when things get out of whack. The problem with QCMS is it relies on your buddy station's pressures to create the "analysis" field, if the analysis includes several poorly calibrated pressures, then the analysis is not going to be very useful. That's why I say use a pressure sensor you know is professionally maintained which in most cases will be the local airport ASOS/AWOS. > Chris Howard > chris at yipyap.com > _______________________________________________ > wxqc mailing list > wxqc at lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050202/66e64e11/attachment-0002.html -------------- next part -------------- An embedded message was scrubbed... From: dshelms at comcast.net Subject: Re: [wxqc] more on BP calibration Date: Wed, 2 Feb 2005 19:54:55 +0000 Size: 684 Url: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050202/66e64e11/attachment-0002.mht From chris at yipyap.com Wed Feb 2 17:17:50 2005 From: chris at yipyap.com (chris at yipyap.com) Date: Wed, 2 Feb 2005 22:17:50 -0000 Subject: [wxqc] Re: more on BP calibration Message-ID: <200502022217.j12MHoKl010603@web150.megawebservers.com> Thanks to both David and Phillip. I think I have a plan now. During the quiet part of the day today I could track my station with the Fort Collins METARS in a predictable way by subtracting 0.7 from my current raw figure (inches of mercury), then apply Phillip's altitude adjustment procedure. That worked until the breeze came up in Fort Collins. Even afterward it was pretty close, and on a gradient with the Fort Collins METARS and a CWOP station in between. I'm pretty convinced. I'm also convinced that the two other CWOP stations closest to me are slightly high in the BP department but not as far off kilter as I am! Chris Howard chris at yipyap.com From sam at wa4phy.net Wed Feb 9 21:05:21 2005 From: sam at wa4phy.net (Sam Drinkard) Date: Wed, 09 Feb 2005 21:05:21 -0500 Subject: [wxqc] Rain gauge discrepancy Message-ID: <420AC161.4030505@wa4phy.net> Altho this might not be strictly within the context of data quality, per-se, I wanted someone else' thoughts on this. Have noticed a decent amount of difference in the quantity of measured rain in my 8" NWS gauge vs. my Davis rain gauge, and the old 4" gauge. With today's rain event the 8" gauge contained 0.75", the Davis gauge recorded 0.62" and the 4" gauge had 0.65" in it. Are the 8" gauges really that much more accurate than a 4" or a tipping bucket that is properly calibrated? The 8" is located about 2' lower, but within 5' of the Davis gauge, and the 4" gauge is located out in the clear but 6' off the ground on the top of a privacy fence. Don't think there would be any turbulence from the house affecting the 8" or the Davis. Do I need to do some calibration on the tipping bucket? This is the 2nd or 3rd time I've noticed a relatively significant difference between the 8" NWS gauge and the Davis tipping bucket gauge. Comments? -- Sam From dshelms at comcast.net Thu Feb 10 00:46:10 2005 From: dshelms at comcast.net (dshelms at comcast.net) Date: Thu, 10 Feb 2005 05:46:10 +0000 Subject: [wxqc] Rain gauge discrepancy Message-ID: <021020050546.16724.420AF5220006CEA60000415422007637049C03040A089C0B@comcast.net> Hi Sam, Two things.... Its documented that tipping buckets can have trouble keeping up with moderate or greater rainfall with excess precip slopping over the cups. We are in the process of publishing siting guidelines for CWOP members. In the siting guide, we recommend that members site their precip gauge at 2.0 feet (0.6 meters) above ground level in an effort to minimize the very real problem of rainfall undercatchment caused by winds blowing up over the leading edge of the rain gauge. Wind speed increases rapidly with even small increases in elevation so it is very possible the cause of the precip differences. The the rule to follow is the lower you site your rain gauge, the better (the opposite of this concept is siting of rain gauges on rooftops is a bad idea). The qualifier if the lower is better rule is to make sure 1) rain falling outside the rain gauge doesn't splash into the gauge, and 2) adjacent trees, walls, and fences don't "shadow" the rain for your rain gauge. At 2 feet, you also need to keep the grass and creeping vines from overgrowing the gauge. We will have the CWOP Siting Guide out for the review in a couple weeks and hope ya'll will give it a good look. Regards, Dave -------------- Original message -------------- > Altho this might not be strictly within the context of data quality, > per-se, I wanted someone else' thoughts on this. > > Have noticed a decent amount of difference in the quantity of > measured rain in my 8" NWS gauge vs. my Davis rain gauge, and the old > 4" gauge. With today's rain event the 8" gauge contained 0.75", the > Davis gauge recorded 0.62" and the 4" gauge had 0.65" in it. Are the > 8" gauges really that much more accurate than a 4" or a tipping bucket > that is properly calibrated? The 8" is located about 2' lower, but > within 5' of the Davis gauge, and the 4" gauge is located out in the > clear but 6' off the ground on the top of a privacy fence. Don't think > there would be any turbulence from the house affecting the 8" or the > Davis. Do I need to do some calibration on the tipping bucket? This is > the 2nd or 3rd time I've noticed a relatively significant difference > between the 8" NWS gauge and the Davis tipping bucket gauge. > > Comments? > > -- > Sam > > _______________________________________________ > wxqc mailing list > wxqc at lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050210/7102d051/attachment-0002.html From ebookbinder at mchsi.com Wed Feb 9 21:17:49 2005 From: ebookbinder at mchsi.com (Evan Bookbinder) Date: Wed, 9 Feb 2005 20:17:49 -0600 Subject: [wxqc] Rain gauge discrepancy References: <420AC161.4030505@wa4phy.net> Message-ID: <044401c50f19$33dc1eb0$6701a8c0@HPLAPTOP> Sam, How heavy was the precipitation and what were the winds like? In addition the opening size differences, you may have differences that exist between a manually measured "can" and a tipping bucket. If it was precipitating heavy enough, it's possible that some of the "tips" in the Davis were missed. The design of the Davis gauges (not to distinguish from other home weather station gauges that are similar) also encourage splash-out. Based on what you've stated, I don't think siting is a problem, nor do I think the difference in guage diameter alone would lead to differences of that magnitude. As for me personally, I will always take the 8" gauge as official and use the automated guage as a way of estimating precipitation w/o having to go outside and check it. In most events I suspect that you notice the readings are similar. It's in extreme events or wintry precipitation where the differences are most significant. You can also check the accuracy of the Davis by taking a measured quantity of water from the NWS guage and pouring it through the Davis (of course disabling it from any logging features). Evan NWS Springfield MO ----- Original Message ----- From: "Sam Drinkard" To: "Discussion of data quality issues" Sent: Wednesday, February 09, 2005 8:05 PM Subject: [wxqc] Rain gauge discrepancy > Altho this might not be strictly within the context of data quality, > per-se, I wanted someone else' thoughts on this. > > Have noticed a decent amount of difference in the quantity of measured > rain in my 8" NWS gauge vs. my Davis rain gauge, and the old 4" gauge. > With today's rain event the 8" gauge contained 0.75", the Davis gauge > recorded 0.62" and the 4" gauge had 0.65" in it. Are the 8" gauges > really that much more accurate than a 4" or a tipping bucket that is > properly calibrated? The 8" is located about 2' lower, but within 5' of > the Davis gauge, and the 4" gauge is located out in the clear but 6' off > the ground on the top of a privacy fence. Don't think there would be any > turbulence from the house affecting the 8" or the Davis. Do I need to do > some calibration on the tipping bucket? This is the 2nd or 3rd time I've > noticed a relatively significant difference between the 8" NWS gauge and > the Davis tipping bucket gauge. > > Comments? > > -- > Sam > > _______________________________________________ > wxqc mailing list > wxqc at lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > From sam at wa4phy.net Thu Feb 10 17:52:39 2005 From: sam at wa4phy.net (Sam Drinkard) Date: Thu, 10 Feb 2005 17:52:39 -0500 Subject: [wxqc] Rain gauge discrepancy In-Reply-To: <044401c50f19$33dc1eb0$6701a8c0@HPLAPTOP> References: <420AC161.4030505@wa4phy.net> <044401c50f19$33dc1eb0$6701a8c0@HPLAPTOP> Message-ID: <420BE5B7.1080506@wa4phy.net> Evan, Best I remember, there was little to no wind, so that kind of rules out the decapture part due to blowing, and there is an elevation difference of maybe 2' between the Davis and the SRG. As for the 4" gauge, it's about 6' or better off the ground, and I expect it to have some differences in readings due to height above ground, but not that different from the Davis gauge. I realize the tipping buckets are for sure, not optimal, but I don't recall seeing that much difference in it and the others until the last few rain events. I suppose I should try to calibrate with a known amount of water at a controlled rate to see if it is losing tips or just out of calibration. None of the rain came down with such intensity that it would have missed a tip I don't think, but anything is possible. I may lower it down to 2' like Dave suggested and then compare readings again. The whole reason I wound up with the 8" gauge was for snow measurement for the AGS area for CAE WFO. I'd not even bothered comparing things till our previous rain event. I'm currently out of town at the Orlando hamfest, so any replys might be delayed... Sam From dshelms at comcast.net Fri Feb 11 01:14:11 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Fri, 11 Feb 2005 01:14:11 -0500 Subject: [wxqc] Rain gauge discrepancy In-Reply-To: <420BE5B7.1080506@wa4phy.net> Message-ID: Sam, I keep a running comparison between my 4" manual gauge (4" is the minimum diameter manual rain gauge NWS will accept "climate" precip measurements from; as Evan says, 8" gauge is the "standard") and my Peet Bros automated heated rain gauge (its a electrode "shorting" gauge, the rain drops complete the circuit as they drip through the gauge's orifice and the gauge counts 0.001" per drop, no moving parts). My "best guess" monthly total precip for climate monitoring purposes is the greatest daily amount from either gauge which is often from the manual gauge. I encourage everyone to use a 4" or larger manual gauge to compare with the automated gauge. Don't use one of the cheaper "wedge" gauges, their diameter is too small. Many automated gauges have test procedures. Peet Bros recommends getting a liquid medicine syringe from your pharmacy (they are free) to carefully measure 10 milli-liters of water, place that amount of water into a paper cup with small pin holes and drain the water into the rain gauge to register a specific precip amount. Dave -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Sam Drinkard Sent: Thursday, February 10, 2005 5:53 PM To: Discussion of data quality issues Subject: Re: [wxqc] Rain gauge discrepancy Evan, Best I remember, there was little to no wind, so that kind of rules out the decapture part due to blowing, and there is an elevation difference of maybe 2' between the Davis and the SRG. As for the 4" gauge, it's about 6' or better off the ground, and I expect it to have some differences in readings due to height above ground, but not that different from the Davis gauge. I realize the tipping buckets are for sure, not optimal, but I don't recall seeing that much difference in it and the others until the last few rain events. I suppose I should try to calibrate with a known amount of water at a controlled rate to see if it is losing tips or just out of calibration. None of the rain came down with such intensity that it would have missed a tip I don't think, but anything is possible. I may lower it down to 2' like Dave suggested and then compare readings again. The whole reason I wound up with the 8" gauge was for snow measurement for the AGS area for CAE WFO. I'd not even bothered comparing things till our previous rain event. I'm currently out of town at the Orlando hamfest, so any replys might be delayed... Sam _______________________________________________ wxqc mailing list wxqc at lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From dshelms at comcast.net Fri Feb 11 07:25:17 2005 From: dshelms at comcast.net (Sandy and David Helms) Date: Fri, 11 Feb 2005 07:25:17 -0500 Subject: [wxqc] Rain gauge discrepancy In-Reply-To: Message-ID: One more thing... its very important that your rain gauge(s) are absolutely level. I use a 4 foot bubble level to do this. Dave -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Sandy and David Helms Sent: Friday, February 11, 2005 1:14 AM To: Discussion of data quality issues Subject: RE: [wxqc] Rain gauge discrepancy Sam, I keep a running comparison between my 4" manual gauge (4" is the minimum diameter manual rain gauge NWS will accept "climate" precip measurements from; as Evan says, 8" gauge is the "standard") and my Peet Bros automated heated rain gauge (its a electrode "shorting" gauge, the rain drops complete the circuit as they drip through the gauge's orifice and the gauge counts 0.001" per drop, no moving parts). My "best guess" monthly total precip for climate monitoring purposes is the greatest daily amount from either gauge which is often from the manual gauge. I encourage everyone to use a 4" or larger manual gauge to compare with the automated gauge. Don't use one of the cheaper "wedge" gauges, their diameter is too small. Many automated gauges have test procedures. Peet Bros recommends getting a liquid medicine syringe from your pharmacy (they are free) to carefully measure 10 milli-liters of water, place that amount of water into a paper cup with small pin holes and drain the water into the rain gauge to register a specific precip amount. Dave -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Sam Drinkard Sent: Thursday, February 10, 2005 5:53 PM To: Discussion of data quality issues Subject: Re: [wxqc] Rain gauge discrepancy Evan, Best I remember, there was little to no wind, so that kind of rules out the decapture part due to blowing, and there is an elevation difference of maybe 2' between the Davis and the SRG. As for the 4" gauge, it's about 6' or better off the ground, and I expect it to have some differences in readings due to height above ground, but not that different from the Davis gauge. I realize the tipping buckets are for sure, not optimal, but I don't recall seeing that much difference in it and the others until the last few rain events. I suppose I should try to calibrate with a known amount of water at a controlled rate to see if it is losing tips or just out of calibration. None of the rain came down with such intensity that it would have missed a tip I don't think, but anything is possible. I may lower it down to 2' like Dave suggested and then compare readings again. The whole reason I wound up with the 8" gauge was for snow measurement for the AGS area for CAE WFO. I'd not even bothered comparing things till our previous rain event. I'm currently out of town at the Orlando hamfest, so any replys might be delayed... Sam _______________________________________________ wxqc mailing list wxqc at lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc _______________________________________________ wxqc mailing list wxqc at lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc From tbarstow at earthlink.net Sun Feb 13 15:43:49 2005 From: tbarstow at earthlink.net (Tom Barstow) Date: Sun, 13 Feb 2005 15:43:49 -0500 Subject: [wxqc] QC Reports Message-ID: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> I'm new to this QC reporting and need some help. Below is a copy of my QC report and can anyone tell me what it's saying and how to fix the problem. I get this report all the time. I run a Davis Vantage Pro 2 with Virtual Weather Station as software. DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 12-FEB-2005 Errs CW2967 * 0/42 * 0/42 * 0/42 * 2/42 * 2/42 Note that times are in UTC. The values displayed are 'Observed (error)' The error value is 'analysis - observed'. I.e. if your observed value is higher than the computed value, then the error will be negative. You have to pick out the reading that is in error. The row with the time of 'Smry' is a daily summary and the data is 'mean(standard deviation)' for each observation during that day. DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 07-FEB-2005 Errs CW2967 * 0/96 * 3/96 * 0/96 * 0/96 * 0/96 From alan at batie.org Sun Feb 13 19:27:25 2005 From: alan at batie.org (Alan Batie) Date: Sun, 13 Feb 2005 16:27:25 -0800 Subject: [wxqc] QC Reports In-Reply-To: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> References: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> Message-ID: <420FF06D.6090404@batie.org> Tom Barstow wrote: > 12-FEB-2005 Errs CW2967 * 0/42 * 0/42 * 0/42 * 2/42 * 2/42 > > Note that times are in UTC. The values displayed are 'Observed (error)' > The error value is 'analysis - observed'. I think the problem is that the description doesn't match the report: if I remember right, it's more like "the values displayed are #errs/#num reports, where #errs is determined by comparing your data with a statistical analysis of neighboring weather stations". In looking at last week's weekly report I received: DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 06-FEB-2005 Errs CW2408 * * 0/95 * * 2/95 * 2/95 06-FEB-2005 Week CW2408 * *0.71(1.78)* *0.27(96.4)* -1.1( 1.6) The "Week" row (assuming it's the same as "Smry" only over a whole week) is supposed to be "mean(standard deviation)", but if anything, it looks more like "std dev (mean)". I'm not sure what "POT TEMP" is, but am assuming "DD" is "Degree Days" as I can't think what else it would be and I seem to recall hearing that term somewhere. Don't remember what they are though. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3196 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050213/058729bb/attachment.bin From Evan.Bookbinder at noaa.gov Sun Feb 13 19:45:35 2005 From: Evan.Bookbinder at noaa.gov (Evan Bookbinder) Date: Mon, 14 Feb 2005 00:45:35 +0000 Subject: [wxqc] QC Reports In-Reply-To: <420FF06D.6090404@batie.org> References: <6.2.1.2.0.20050213153915.01e3fe58@mail.earthlink.net> <420FF06D.6090404@batie.org> Message-ID: <420FF4AF.2040002@noaa.gov> It's the number of errors and total number of reports for the period. In your case, you don't have any problems! FYI, POT TEMP is potential temperature. It's basically the result of taking everyone's temperature and putting them on an even surface (1000mb). This helps remove non-existant errors that would be caused by elevation differences. In otherwords, if I'm at 50 degrees and Joe is 10 miles away but 3000 feet higher elevation at 32 degrees, the potential temperature would still be nearly equal. DD is wind direction in degrees. I don't have your full report, but it sounds like there may be errors in the description fields that aren't matching up with the numbers that are shown. Hopefully someone in the know can take a look at this further. Evan WFO Springfield, MO Alan Batie wrote: > Tom Barstow wrote: > >> 12-FEB-2005 Errs CW2967 * 0/42 * 0/42 * 0/42 * 2/42 >> * 2/42 >> >> Note that times are in UTC. The values displayed are 'Observed (error)' >> The error value is 'analysis - observed'. > > > I think the problem is that the description doesn't match the report: > if I remember right, it's more like "the values displayed are > #errs/#num reports, where #errs is determined by comparing your data > with a statistical analysis of neighboring weather stations". > > In looking at last week's weekly report I received: > > DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD > * FF > * (MB) * (DEG F) * (DEG F) * (DEG) > * (KNT) > 06-FEB-2005 Errs CW2408 * * 0/95 * * 2/95 > * 2/95 > 06-FEB-2005 Week CW2408 * *0.71(1.78)* > *0.27(96.4)* -1.1( 1.6) > > The "Week" row (assuming it's the same as "Smry" only over a whole > week) is supposed to be "mean(standard deviation)", but if anything, > it looks more like "std dev (mean)". > > I'm not sure what "POT TEMP" is, but am assuming "DD" is "Degree Days" > as I can't think what else it would be and I seem to recall hearing > that term somewhere. Don't remember what they are though. > >------------------------------------------------------------------------ > >_______________________________________________ >wxqc mailing list >wxqc at lists.gladstonefamily.net >http://pond1.gladstonefamily.net