From gerry.creager at tamu.edu Sun Jul 1 00:02:41 2007 From: gerry.creager at tamu.edu (Gerry Creager) Date: Sun, 01 Jul 2007 00:02:41 -0500 Subject: [wxqc] New idea in Solar shielding In-Reply-To: <001101c7bb91$5a1a17e0$0801a8c0@hush> References: <003101c7bb60$eeaf9f50$0801a8c0@hush> <007401c7bb64$eca97240$03371e0a@Artemis> <001101c7bb91$5a1a17e0$0801a8c0@hush> Message-ID: <46873571.8030708@tamu.edu> Hmmm. And I'll have to mull over this before I can have an opinion on the angle of declination derived from a solar panel being ideal for more than the obvious max solar angle concept. I'm intrigued by this approach but don't have the time or facilities to test it against simple aspiration at this point. HOWEVER... the angle of a solar panel is generally derived from the latitude and is used to maximize solar exposure. As most solar arrays aren't "smart" they're pointed south, and generally angled at the longitude of the site off the zenith axis. This gives a good approximation of "best sun angle" and is usually easy to determine or measure. Creating air movement via convection would tend to move warmed air past the sensor. Whether the angle of the tube promotes "easier" movement and thus less heating is another issue. Bears some study. Use of an active fan suggests a constant volume movement which should entrain air not subjected to heating in the enclosure. If you can't verify that is happening, I'm a bit skeptical of total success. Still, an interesting concept. gerry Paul Grace wrote: > I ahave a few questions: > The "warm air floating upward" is, by definition, warmer than ambient, isn't > it? > "Cooler, denser air"? Where does this air come from, and what cools it? > How is the "perfect angle" calculated, does it change according to latitude > & season, like solar panels? > > I bet the breeze scavenges the tube. > > But congratulations, you're not crazy! ;-) > It seems the tube is horizontal enough to catch breezes if they are flowing > the right direction, and being a little off level, it doesn't pool hot air > as much, and could "chimney" some. > But if the breeze is gently moving from the high end to the low, you'll get > a spike. Maybe you should mount it on a wind vane so it never points the > "wrong" way? > To test your tube, put a sensor in each end, and gather some data on the > differences. > > _____ > > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bryce Alexander > Sent: Saturday, June 30, 2007 15:21 > To: 'Discussion of weather data quality issues' > Subject: [wxqc] New idea in Solar shielding > > > > Actually not so new, I brought this one up a couple of months ago and the > majority voted me crazy. I recall that the consensus is that a temp sensor > in AZ must be actively aspirated no matter what. That no matter how it is > configured Arizona climate is such that solar radiation will always be an > issue and fans are mandatory. > > > > OK, now the proof is in the pudding, after running my new design for several > months, and right now, while we are at 110F and single digit humidity this > would be the very best time to see a solar radiation issue and there doesn't > appear to be any. > > > > The basic concept is so simple that it is no wonder that most people were > skeptical, it is simply a plastic pipe (an ABS sewer pipe painted white to > be exact) set at an angle such that the warm air will float upward out of > the solar shield, while the cooler denser air will fall downward. It is in > essence a passive self aspirating solar shield. > > > > To see pictures of what I am talking about, along with the actual readings, > see: http://weather.gladstonefamily.net/site/C7166 > > > > I got the idea from reading some of the studies where various designs were > "baked off" in a comparative study. I noticed that a horizontal pipe > performed nearly as well as any other arrangement, but from years of > watching how AZ heat accumulates I was skeptical that a horizontal pipe > would remain at ambient temps during hot days like today. Still air can > built up in the pipe and must be cleared in some manner. Then one day I was > looking at a solar panel and the angle it was sitting at made me realize > that it would be a perfect angle for heat to rise away from the sensor as it > built up along the wall of the pipe. > > > > This is such a simple design it would be nice to get some correlation, > anyone else willing to try it out and then report back on how it compares to > your own favorite shielding? > > > > I have compared with a sling psycrometer, and It tracks exactly to the > sensor in the shield; day and night. > > > > ------------------------------------------------------------------------ > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -- Gerry Creager -- gerry.creager at tamu.edu Texas Mesonet -- AATLT, Texas A&M University Cell: 979.229.5301 Office: 979.458.4020 FAX 979.862.3983 MAIL: AATLT, 3139 TAMU Physical: 1700 Research Parkway, Suite 160, College Station, TX 77843-3139 From Edith.Thornburg at verizon.net Sun Jul 1 07:04:34 2007 From: Edith.Thornburg at verizon.net (Edith Thornburg) Date: Sun, 01 Jul 2007 08:04:34 -0400 Subject: [wxqc] OT: changing the name of the post to be relevant In-Reply-To: <011101c7bb75$1be6d970$0501a8c0@Richardn> Message-ID: <000b01c7bbd7$ff5a9e00$6400a8c0@BLACK> Another problem is when the topic changes but the post subject does not reflect it. Please, if you change the subject, change the subject line as well. Edith If you want to know what the weather is like in our back yard, visit my new updated web pages?at: http://mysite.verizon.net/vze4fyr3/suffern.pomona.ny/ In the Pomona portion of Suffern, NY It is a wireless Davis Vantage Pro2 plus -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Richard Sent: Saturday, June 30, 2007 8:17 PM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] OT: Hosting a Web Server with a Dynamic IP (Cable) There are two ways to solve this: 1. Delete messages that offend you. 2. Scan the messages, and if you see one with a subject that doesn't interest you...Then don't read it! Richard www.n7tgb.net -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Victor Engel Sent: Saturday, June 30, 2007 3:07 PM To: paulgrace at lookoutranch.com; Discussion of weather data quality issues Subject: Re: [wxqc] OT: Hosting a Web Server with a Dynamic IP (Cable) On 6/30/07, Paul Grace wrote: > It's pretty simple to killfile on the text "OT" if anyone is that offended. > They'd never be bothered again. I consider this to be a copout. We shouldn't have to set up filters to view only on-topic posts. The whole point of having a forum directed at a particular topic is to get posts that are prescreened. Victor _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.9.14/880 - Release Date: 6/29/2007 2:15 PM From bweybrecht at bellsouth.net Sun Jul 1 08:06:17 2007 From: bweybrecht at bellsouth.net (Bob) Date: Sun, 1 Jul 2007 09:06:17 -0400 Subject: [wxqc] New idea in Solar shielding In-Reply-To: <46873571.8030708@tamu.edu> Message-ID: <002a01c7bbe0$9cade920$0a5a210a@wsr88d> -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Gerry Creager Sent: Sunday, July 01, 2007 1:03 AM To: paulgrace at lookoutranch.com; Discussion of weather data quality issues Subject: Re: [wxqc] New idea in Solar shielding Hmmm. And I'll have to mull over this before I can have an opinion on the angle of declination derived from a solar panel being ideal for more than the obvious max solar angle concept. I'm intrigued by this approach but don't have the time or facilities to test it against simple aspiration at this point. HOWEVER... the angle of a solar panel is generally derived from the latitude and is used to maximize solar exposure. As most solar arrays aren't "smart" they're pointed south, and generally angled at the longitude of the site off the zenith axis. This gives a good approximation of "best sun angle" and is usually easy to determine or measure. Creating air movement via convection would tend to move warmed air past the sensor. Whether the angle of the tube promotes "easier" movement and thus less heating is another issue. Bears some study. Use of an active fan suggests a constant volume movement which should entrain air not subjected to heating in the enclosure. If you can't verify that is happening, I'm a bit skeptical of total success. Still, an interesting concept. Gerry This is along the lines of an idea I've played with. This is on a vertical scale. The bottom of the enclosure is white 2 inch PVC - maybe six inches long. The upper part of the enclosure is black 2 inch ABS maybe a foot long cemented to the lower part of the enclosure. The very top of the assembly has a white PVC 180 on it to keep rain out. The sensor is placed just inside the lower opening. Screen or fiberglass matt over both openings keeps the critters out. The sun heats the ABS. There is significant convection, and it results in makeup air being pulled into the lower opening. No moving parts. From ikishk+wxqc at gmail.com Sun Jul 1 11:43:57 2007 From: ikishk+wxqc at gmail.com (Isaac Kishk (CW6261)) Date: Sun, 1 Jul 2007 11:43:57 -0500 Subject: [wxqc] New idea in Solar shielding In-Reply-To: <002a01c7bbe0$9cade920$0a5a210a@wsr88d> References: <46873571.8030708@tamu.edu> <002a01c7bbe0$9cade920$0a5a210a@wsr88d> Message-ID: See, but that's actually pulling the air over the sensor. the heat is away from it, pulling air over it from the "outside"". In this other example, the sensor in in the middle of the heat, theres no separation, which gives me some doubts. sure it has the same movement, but its moving artificially warmed air, otherwise theres no movement. My 5w solar panel, charging a $20 autozone lawn&garden battery, running a 12v 80mm fan, aspirating through some PVC, has been doing me well in the humidity of central texas. > > This is along the lines of an idea I've played with. This is on a vertical > scale. The bottom of the enclosure is white 2 inch PVC - maybe six inches > long. The upper part of the enclosure is black 2 inch ABS maybe a foot long > cemented to the lower part of the enclosure. The very top of the assembly > has a white PVC 180 on it to keep rain out. The sensor is placed just inside > the lower opening. Screen or fiberglass matt over both openings keeps the > critters out. The sun heats the ABS. There is significant convection, and it > results in makeup air being pulled into the lower opening. No moving parts. > > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > -- www.kishk.org www.poutcarriers.com From paulgrace at lookoutranch.com Sun Jul 1 11:48:58 2007 From: paulgrace at lookoutranch.com (Paul Grace) Date: Sun, 1 Jul 2007 09:48:58 -0700 Subject: [wxqc] New idea in Solar shielding In-Reply-To: <002a01c7bbe0$9cade920$0a5a210a@wsr88d> References: <46873571.8030708@tamu.edu> <002a01c7bbe0$9cade920$0a5a210a@wsr88d> Message-ID: <005001c7bbff$bd22af50$0801a8c0@hush> This is a horizontal tube (already known to be pretty good, aspirated by any fortunate breeze that isn't perpendicular to the tube), inclined somewhat, so it drains warm air somewhat better. There is no "magic angle", contrary to the explanation, 45* would work as well. I think a comparison to a normal horizontal (but otherwise identical) tube would show very little difference, but it should be better than horizontal I think. I do not think it would match the performance of a simple fan-aspirated shield, but it's simple enough to test, and as long as it's an improvement on the horizontal tube, it's an improvement. It costs almost nothing, it's extremely reliable. It could be tested for performance, then everyone with tubes should tilt them. (assuming it performs measurably better) -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bob Sent: Sunday, July 01, 2007 06:06 To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] New idea in Solar shielding -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Gerry Creager Sent: Sunday, July 01, 2007 1:03 AM To: paulgrace at lookoutranch.com; Discussion of weather data quality issues Subject: Re: [wxqc] New idea in Solar shielding Hmmm. And I'll have to mull over this before I can have an opinion on the angle of declination derived from a solar panel being ideal for more than the obvious max solar angle concept. I'm intrigued by this approach but don't have the time or facilities to test it against simple aspiration at this point. HOWEVER... the angle of a solar panel is generally derived from the latitude and is used to maximize solar exposure. As most solar arrays aren't "smart" they're pointed south, and generally angled at the longitude of the site off the zenith axis. This gives a good approximation of "best sun angle" and is usually easy to determine or measure. Creating air movement via convection would tend to move warmed air past the sensor. Whether the angle of the tube promotes "easier" movement and thus less heating is another issue. Bears some study. Use of an active fan suggests a constant volume movement which should entrain air not subjected to heating in the enclosure. If you can't verify that is happening, I'm a bit skeptical of total success. Still, an interesting concept. Gerry This is along the lines of an idea I've played with. This is on a vertical scale. The bottom of the enclosure is white 2 inch PVC - maybe six inches long. The upper part of the enclosure is black 2 inch ABS maybe a foot long cemented to the lower part of the enclosure. The very top of the assembly has a white PVC 180 on it to keep rain out. The sensor is placed just inside the lower opening. Screen or fiberglass matt over both openings keeps the critters out. The sun heats the ABS. There is significant convection, and it results in makeup air being pulled into the lower opening. No moving parts. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From ashokmpatel at gujaratweather.com Mon Jul 2 09:19:02 2007 From: ashokmpatel at gujaratweather.com (ashokmpatel at gujaratweather.com) Date: Mon, 02 Jul 2007 10:19:02 -0400 Subject: [wxqc] Over reporting of Rainfall on Wunderground Message-ID: <6237948.709981183385942514.JavaMail.servlet@perfora> I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain today 2nd July. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch for one rain bucket tip. Wunderground is reporting 223 mm. based on my data. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com From ashokmpatel at gujaratweather.com Mon Jul 2 09:21:33 2007 From: ashokmpatel at gujaratweather.com (ashokmpatel at gujaratweather.com) Date: Mon, 02 Jul 2007 10:21:33 -0400 Subject: [wxqc] Over reporting of Rainfall by Wunderground Message-ID: <5722053.710491183386094003.JavaMail.servlet@perfora> Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 74.6 mm (approx. 3 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com From ashokmpatel at gujaratweather.com Mon Jul 2 09:33:26 2007 From: ashokmpatel at gujaratweather.com (ashokmpatel at gujaratweather.com) Date: Mon, 02 Jul 2007 10:33:26 -0400 Subject: [wxqc] Over reporting of rainfall by Wunderground Message-ID: <9351317.712261183386806352.JavaMail.servlet@perfora> Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Wunderground is reporting 223 mm, which is 25% more than what I have measured. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com From garbal54 at gmail.com Mon Jul 2 15:10:15 2007 From: garbal54 at gmail.com (Gary B) Date: Mon, 2 Jul 2007 17:10:15 -0300 Subject: [wxqc] MADIS Message-ID: <001e01c7bce5$023b1e70$6401a8c0@GARY> Is it possible that the MADIS calibration info could be "slightly askew" if the site that is being measured is away from the open ocean, yet it appears many of the stations they are using as "base info" are located right at the ocean shoreline, or in some cases actually on buoys in the Atlantic? I am unsure of how "base readings" are done and what criteria is used to select these stations. My main sensor problem seems to be humidity (dewpoint). Thanks Gary Balcom (CW8232) (INSDARTM2 on wunderground) -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070702/36427261/attachment.htm From Derek.deBastos at xmradio.com Tue Jul 3 11:18:35 2007 From: Derek.deBastos at xmradio.com (de Bastos, Derek) Date: Tue, 3 Jul 2007 12:18:35 -0400 Subject: [wxqc] Davis Vantage Pro2 Rain Gauge Calibration In-Reply-To: <4682BBD0.1000507@earthlink.net> References: <46827328.5080300@earthlink.net> <00ec01c7b8d0$63f5f400$0200a8c0@dell1500> <000f01c7b8d8$aeafec00$0200a8c0@dell1500> <4682BBD0.1000507@earthlink.net> Message-ID: Trevor wrote: >The rain gauge has never been adjusted since the factory. >It required an adjustment of +12% to get from 84 tips of >the bucket (.01 in.per tip) to the 100 tips require to >measure 1" of water. FWIW, I checked the calibration of my VP1 after changing its battery this past weekend. Like Trevor's, my rain gauge has not been adjusted since it left the factory. Coincidently (or not), I got a nearly identical result-- my gauge was reading low (81 tips for 1") and it took around two turns on the screws to fix it. Before reading this thread, I would have not suspected my gauge could be this far off. Derek CW2463 From blznqgr at earthlink.net Tue Jul 3 14:12:30 2007 From: blznqgr at earthlink.net (Trevor) Date: Tue, 03 Jul 2007 14:12:30 -0500 Subject: [wxqc] Davis Vantage Pro2 Rain Gauge Calibration In-Reply-To: References: <46827328.5080300@earthlink.net> <00ec01c7b8d0$63f5f400$0200a8c0@dell1500> <000f01c7b8d8$aeafec00$0200a8c0@dell1500> <4682BBD0.1000507@earthlink.net> Message-ID: <468A9F9E.7070400@earthlink.net> It pays to check....I check another station that I run (Davis Vantage Pro1) and it was right on the money...so go figure.....some come out of the factory A-ok and some don't!! de Bastos, Derek wrote: > Trevor wrote: > > >> The rain gauge has never been adjusted since the factory. >> It required an adjustment of +12% to get from 84 tips of >> the bucket (.01 in.per tip) to the 100 tips require to >> measure 1" of water. >> > > FWIW, I checked the calibration of my VP1 after changing its battery > this past weekend. Like Trevor's, my rain gauge has not been adjusted > since it left the factory. > > Coincidently (or not), I got a nearly identical result-- my gauge was > reading low (81 tips for 1") and it took around two turns on the screws > to fix it. Before reading this thread, I would have not suspected my > gauge could be this far off. > > Derek > CW2463 > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > From brillig at gmail.com Tue Jul 3 13:15:48 2007 From: brillig at gmail.com (Victor Engel) Date: Tue, 3 Jul 2007 13:15:48 -0500 Subject: [wxqc] Davis Vantage Pro2 Rain Gauge Calibration In-Reply-To: <468A9F9E.7070400@earthlink.net> References: <46827328.5080300@earthlink.net> <00ec01c7b8d0$63f5f400$0200a8c0@dell1500> <000f01c7b8d8$aeafec00$0200a8c0@dell1500> <4682BBD0.1000507@earthlink.net> <468A9F9E.7070400@earthlink.net> Message-ID: I'm just waiting for it to stop raining so I can check mine . BTW, until this thread started, I was unaware of an adjustment screw. I'm going to have to pull out the manual to see where it's located. On 7/3/07, Trevor wrote: > It pays to check....I check another station that I run (Davis Vantage > Pro1) and it was right on the money...so go figure.....some come out of > the factory A-ok and some don't!! > > de Bastos, Derek wrote: > > Trevor wrote: > > > > > >> The rain gauge has never been adjusted since the factory. > >> It required an adjustment of +12% to get from 84 tips of > >> the bucket (.01 in.per tip) to the 100 tips require to > >> measure 1" of water. > >> > > > > FWIW, I checked the calibration of my VP1 after changing its battery > > this past weekend. Like Trevor's, my rain gauge has not been adjusted > > since it left the factory. > > > > Coincidently (or not), I got a nearly identical result-- my gauge was > > reading low (81 tips for 1") and it took around two turns on the screws > > to fix it. Before reading this thread, I would have not suspected my > > gauge could be this far off. > > > > Derek > > CW2463 > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From webmaster at saratoga-weather.org Tue Jul 3 13:37:28 2007 From: webmaster at saratoga-weather.org (Ken True) Date: Tue, 03 Jul 2007 11:37:28 -0700 Subject: [wxqc] Davis Vantage Pro2 Rain Gauge Calibration In-Reply-To: References: <46827328.5080300@earthlink.net> <00ec01c7b8d0$63f5f400$0200a8c0@dell1500> <000f01c7b8d8$aeafec00$0200a8c0@dell1500> <4682BBD0.1000507@earthlink.net> <468A9F9E.7070400@earthlink.net> Message-ID: <468A9768.8020906@saratoga-weather.org> I haven't seen the adjustment for the tipping buckets mentioned in later ISS documentation, but the earlier separate rain collector II ( http://www.davisnet.com/product_documents/weather/manuals/rain_collector.pdf ) on page 11 shows a diagram of the adjustment screw. One turn clockwise will lower the reading by 6% while one turn anti-clockwise will raise the reading by 6%. Both screws have to be rotated in the same direction and the same amount to properly do the adjustment. So two anti-clockwise turns on both screws should raise the measurement by about 12%. I had compared my VP1 collector to a neighbors older VP1 and a manual 4" collector and found I needed to adjust the VP collector up by about 11% to match the readings. Now all three are within 0.01 (one tip) for a rain event. Ken True CW1792 http://saratoga-weather.org/ Victor Engel wrote: > I'm just waiting for it to stop raining so I can check mine . BTW, > until this thread started, I was unaware of an adjustment screw. I'm > going to have to pull out the manual to see where it's located. > > On 7/3/07, Trevor wrote: > >> It pays to check....I check another station that I run (Davis Vantage >> Pro1) and it was right on the money...so go figure.....some come out of >> the factory A-ok and some don't!! >> >> de Bastos, Derek wrote: >> >>> Trevor wrote: >>> >>> >>> >>>> The rain gauge has never been adjusted since the factory. >>>> It required an adjustment of +12% to get from 84 tips of >>>> the bucket (.01 in.per tip) to the 100 tips require to >>>> measure 1" of water. >>>> >>>> >>> FWIW, I checked the calibration of my VP1 after changing its battery >>> this past weekend. Like Trevor's, my rain gauge has not been adjusted >>> since it left the factory. >>> >>> Coincidently (or not), I got a nearly identical result-- my gauge was >>> reading low (81 tips for 1") and it took around two turns on the screws >>> to fix it. Before reading this thread, I would have not suspected my >>> gauge could be this far off. >>> >>> Derek >>> CW2463 >>> _______________________________________________ >>> wxqc mailing list >>> Post messages to wxqc at lists.gladstonefamily.net >>> To unsubcribe or change delivery options, please go to: >>> http://server.gladstonefamily.net/mailman/listinfo/wxqc >>> >>> The contents of this message are the responsibility of the author. >>> >>> >>> >> _______________________________________________ >> wxqc mailing list >> Post messages to wxqc at lists.gladstonefamily.net >> To unsubcribe or change delivery options, please go to: >> http://server.gladstonefamily.net/mailman/listinfo/wxqc >> >> The contents of this message are the responsibility of the author. >> >> > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From bryce at azlab.net Tue Jul 3 17:45:20 2007 From: bryce at azlab.net (Bryce Alexander) Date: Tue, 3 Jul 2007 15:45:20 -0700 Subject: [wxqc] Over reporting of rainfall by Wunderground In-Reply-To: <9351317.712261183386806352.JavaMail.servlet@perfora> Message-ID: <020f01c7bdc3$d8ee5980$03371e0a@Artemis> I use neither Davis, nor Wunderground, however I have many years of working on computers so I am going to take a shot. Wunderground simply takes what it gets. They do not post-process the data to try to convert it. They do however want the data in inches, not metric, so I would suspect that the problem is in your software. It is probably reporting the data to Wunderground as "normal parameters" (0.1in) for a tipping bucket and not making the conversion before sending the data off to Wunderground. I would bet that if you recalibrate your bucket to 0.25mm the data would then be correct, but then you still need to make the conversions for your local display. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of ashokmpatel at gujaratweather.com Sent: Monday, July 02, 2007 7:33 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Over reporting of rainfall by Wunderground Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Wunderground is reporting 223 mm, which is 25% more than what I have measured. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From lwood at mountainbase.com Tue Jul 3 18:36:37 2007 From: lwood at mountainbase.com (lwood at mountainbase.com) Date: Tue, 03 Jul 2007 16:36:37 -0700 Subject: [wxqc] Davis Vantage Pro 2 Rain Gauge Calibration Message-ID: <20070703163637.b014af6efb42cca08111bb1cc252e7a0.c4d833816b.wbe@email.secureserver.net> Hi Victor The adjustment screws are located just below the tipping buckets. A counter clockwise turn raises the screw, restricting the downward movement of the bucket. This allows the buckets to tip with less accumulation. Shortening the screw, requires the bucket to travel farther and thus more weight on the opposite end to tip the bucket. Lance CW1020 From webmaster at memphisweather.net Wed Jul 4 11:04:31 2007 From: webmaster at memphisweather.net (Erik Proseus) Date: Wed, 4 Jul 2007 11:04:31 -0500 Subject: [wxqc] Over reporting of rainfall by Wunderground In-Reply-To: <020f01c7bdc3$d8ee5980$03371e0a@Artemis> References: <9351317.712261183386806352.JavaMail.servlet@perfora> <020f01c7bdc3$d8ee5980$03371e0a@Artemis> Message-ID: <000001c7be55$0215f700$6800a8c0@PROSEUSDESKTOP> Ashok, Just out of curiousity, have you installed the metric rain adapter that comes with the VP2 into your sensor suite? From the manual, "This adapter adds weight to the tipping mechanism, adjusting it to tip for every 0.2 mm of rainfall instead of every 0.01." --Erik -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bryce Alexander Sent: Tuesday, July 03, 2007 5:45 PM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Over reporting of rainfall by Wunderground I use neither Davis, nor Wunderground, however I have many years of working on computers so I am going to take a shot. Wunderground simply takes what it gets. They do not post-process the data to try to convert it. They do however want the data in inches, not metric, so I would suspect that the problem is in your software. It is probably reporting the data to Wunderground as "normal parameters" (0.1in) for a tipping bucket and not making the conversion before sending the data off to Wunderground. I would bet that if you recalibrate your bucket to 0.25mm the data would then be correct, but then you still need to make the conversions for your local display. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of ashokmpatel at gujaratweather.com Sent: Monday, July 02, 2007 7:33 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Over reporting of rainfall by Wunderground Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Wunderground is reporting 223 mm, which is 25% more than what I have measured. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From ashokmpatel at yahoo.com Wed Jul 4 21:28:09 2007 From: ashokmpatel at yahoo.com (Ashok Patel) Date: Wed, 4 Jul 2007 19:28:09 -0700 (PDT) Subject: [wxqc] Over reporting of rainfall by Wunderground In-Reply-To: <000001c7be55$0215f700$6800a8c0@PROSEUSDESKTOP> Message-ID: <216975.67749.qm@web51506.mail.re2.yahoo.com> Erik, Yes I have installed the metric adapter as per instructions in the Vantage Pro 2 manual. The problem is that as per my record, there was 177 mm. on July 2nd. 2007 which Wunderground is reporting as 224.8 mm. This is approx. 25 % more than my reading. Strangely, Wunderground is way out on 3rd. July for reporting rainfall of similar 224.8 mm. instead of 44.8 mm. recorded by me. Also my rainfall readings are comparable with that recorded in Rajkot city where my Weather Statiob is located. Ashok Patel CW8030 RingRoad Weather Station http://www.GujaratWeather.com Erik Proseus wrote: Ashok, Just out of curiousity, have you installed the metric rain adapter that comes with the VP2 into your sensor suite? From the manual, "This adapter adds weight to the tipping mechanism, adjusting it to tip for every 0.2 mm of rainfall instead of every 0.01." --Erik -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bryce Alexander Sent: Tuesday, July 03, 2007 5:45 PM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Over reporting of rainfall by Wunderground I use neither Davis, nor Wunderground, however I have many years of working on computers so I am going to take a shot. Wunderground simply takes what it gets. They do not post-process the data to try to convert it. They do however want the data in inches, not metric, so I would suspect that the problem is in your software. It is probably reporting the data to Wunderground as "normal parameters" (0.1in) for a tipping bucket and not making the conversion before sending the data off to Wunderground. I would bet that if you recalibrate your bucket to 0.25mm the data would then be correct, but then you still need to make the conversions for your local display. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of ashokmpatel at gujaratweather.com Sent: Monday, July 02, 2007 7:33 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Over reporting of rainfall by Wunderground Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Wunderground is reporting 223 mm, which is 25% more than what I have measured. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. --------------------------------- Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070704/92968ba0/attachment-0001.htm From Norm.Shea at kiawah-owners.org Wed Jul 4 22:11:33 2007 From: Norm.Shea at kiawah-owners.org (Norm Shea) Date: Wed, 4 Jul 2007 23:11:33 -0400 Subject: [wxqc] Over reporting of rainfall by Wunderground In-Reply-To: <216975.67749.qm@web51506.mail.re2.yahoo.com> References: <000001c7be55$0215f700$6800a8c0@PROSEUSDESKTOP> <216975.67749.qm@web51506.mail.re2.yahoo.com> Message-ID: <001101c7beb2$312d7fb0$0201000a@maintenance.local> Below is a discussion from the end of May. Maybe those of us who use WU should make a more concerted effort to have WU address this situation. It's sounding like it is fairly common. Norm CW6689 Norm Shea Director, Lakes Management Kiawah Island Community Association Inc 20 Kestrel Court, Kiawah Island, SC 29455 Phone 843-768-2315 x 255 Fax 843-768-0298 Mobile 843-708-3608 Norm.Shea at kiawah-owners.org --- www.kiawah-owners.org I've experienced similar, though not as significant, discrepancies with WU. I have relayed this information to them but have not received a response. Norm Norm Shea Director, Lakes Management Kiawah Island Community Association Inc 20 Kestrel Court, Kiawah Island, SC 29455 Phone 843-768-2315 x 255 Fax 843-768-0298 Mobile 843-708-3608 Norm.Shea at kiawah-owners.org --- www.kiawah-owners.org _____ From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Erik Proseus Sent: Thursday, 31 May 2007 10:09 To: Discussion of weather data quality issues Subject: Re: [wxqc] Problem with monthly total rainfall on WU Hello Rich, Not sure if the rainfall amounts are correct, but on your Weather Underground page, if you look at the monthly view for May (http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KCOCOLOR78 &day=1&year=2007&month=5&graphspan=month) there was more than 3" of rain reported each day on the 2nd, 4th, 5th, and 6th. This is where it is getting it's 16"+ of rain for the month. I'm not sure that you can change what is reported on Weather Underground for previous days, if it is wrong. You might check those days at the beginning of the month on your software and Weather Underground and see which is correct. Regards, --Erik -------------------------------------------------------- Erik Proseus, Webmaster and Forecaster MemphisWeather.Net e-mail: webmaster at MemphisWeather.Net WXLIVE! - Realtime weather conditions from Bartlett WXLIVE!-Severe Weather - watches and warnings delivered to your e-mail, cell phone, or PDA -------Original Message------- From: Rich Brunnworth Subject: [wxqc] Problem with monthly total rainfall on WU Sent: May 31 '07 01:38 I'm a bit confused, nothing abnormal for a newbie. My station is a LaCrosse 2310, uses Heavy weather to talk to the computer, uses VWS for display and upload to wunderground personal weather stations. OK...... here's the problem: The monthly total rainfall in HW and VWS shows as 6.7 some inches of rain, which is correct. Once the data is sent upstream to wunderground it gets set to 16. some inches of total rain for the month. I've noodled around with the history file of HW and can't see anything wrong which leads me to believe that VWS might be the problem. BUT... since the display on the computer reads correctly I don't think that there is anything wrong with the VWS database. I might be wrong tho. So just off the cuff I'm thinking that somehow weather underground is either multiplying my total somehow, or somewhere along the line the data being sent to WU isn't the database that I think it is. Any ideas what or where the problem might be? Rich This email scanned with AVG antivirus program KCOCOLOR78 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubscribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _____ From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Ashok Patel Sent: Wednesday, 04 Jul 2007 22:28 To: webmaster at memphisweather.net; Discussion of weather data quality issues Subject: Re: [wxqc] Over reporting of rainfall by Wunderground Erik, Yes I have installed the metric adapter as per instructions in the Vantage Pro 2 manual. The problem is that as per my record, there was 177 mm. on July 2nd. 2007 which Wunderground is reporting as 224.8 mm. This is approx. 25 % more than my reading. Strangely, Wunderground is way out on 3rd. July for reporting rainfall of similar 224.8 mm. instead of 44.8 mm. recorded by me. Also my rainfall readings are comparable with that recorded in Rajkot city where my Weather Statiob is located. Ashok Patel CW8030 RingRoad Weather Station http://www.GujaratWeather.com Erik Proseus wrote: Ashok, Just out of curiousity, have you installed the metric rain adapter that comes with the VP2 into your sensor suite? From the manual, "This adapter adds weight to the tipping mechanism, adjusting it to tip for every 0.2 mm of rainfall instead of every 0.01." --Erik -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bryce Alexander Sent: Tuesday, July 03, 2007 5:45 PM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Over reporting of rainfall by Wunderground I use neither Davis, nor Wunderground, however I have many years of working on computers so I am going to take a shot. Wunderground simply takes what it gets. They do not post-process the data to try to convert it. They do however want the data in inches, not metric, so I would suspect that the problem is in your software. It is probably reporting the data to Wunderground as "normal parameters" (0.1in) for a tipping bucket and not making the conversion before sending the data off to Wunderground. I would bet that if you recalibrate your bucket to 0.25mm the data would then be correct, but then you still need to make the conversions for your local display. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of ashokmpatel at gujaratweather.com Sent: Monday, July 02, 2007 7:33 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Over reporting of rainfall by Wunderground Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Wunderground is reporting 223 mm, which is 25% more than what I have measured. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _____ Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070704/21489161/attachment.htm From dsmweather at mchsi.com Wed Jul 4 22:46:14 2007 From: dsmweather at mchsi.com (dsmweather) Date: Wed, 4 Jul 2007 22:46:14 -0500 Subject: [wxqc] wxqc Digest, Vol 33, Issue 3 In-Reply-To: References: Message-ID: <001f01c7beb7$098ce630$3410d80c@S0028183503> It finally rained and I am about 50% off. I also noticed that the pan in the unit wobbles some so the magnet might miss the reed switch... I compared the reading with nearby vp2 stations and they agreed between themselves and my calculations . It looked like the assembler just screwed down the screws and packaged it. It poured about an hour yesterday and it showed up 0.13 inches on that guage. The ground is saturated. I'll have to wait for it to rain to see what happens next. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of wxqc-request at lists.gladstonefamily.net Sent: Wednesday, July 04, 2007 09:20 PM To: wxqc at lists.gladstonefamily.net Subject: wxqc Digest, Vol 33, Issue 3 Send wxqc mailing list submissions to wxqc at lists.gladstonefamily.net To subscribe or unsubscribe via the World Wide Web, visit http://server.gladstonefamily.net/mailman/listinfo/wxqc or, via email, send a message with subject or body 'help' to wxqc-request at lists.gladstonefamily.net You can reach the person managing the list at wxqc-owner at lists.gladstonefamily.net When replying, please edit your Subject line so it is more specific than "Re: Contents of wxqc digest..." Today's Topics: 1. Re: Davis Vantage Pro2 Rain Gauge Calibration (Victor Engel) 2. Re: Davis Vantage Pro2 Rain Gauge Calibration (Ken True) 3. Re: Over reporting of rainfall by Wunderground (Bryce Alexander) 4. Davis Vantage Pro 2 Rain Gauge Calibration (lwood at mountainbase.com) 5. Re: Over reporting of rainfall by Wunderground (Erik Proseus) 6. Re: Over reporting of rainfall by Wunderground (Ashok Patel) ---------------------------------------------------------------------- Message: 1 Date: Tue, 3 Jul 2007 13:15:48 -0500 From: "Victor Engel" Subject: Re: [wxqc] Davis Vantage Pro2 Rain Gauge Calibration To: blznqgr at earthlink.net, "Discussion of weather data quality issues" Message-ID: Content-Type: text/plain; charset=ISO-8859-1; format=flowed I'm just waiting for it to stop raining so I can check mine . BTW, until this thread started, I was unaware of an adjustment screw. I'm going to have to pull out the manual to see where it's located. On 7/3/07, Trevor wrote: > It pays to check....I check another station that I run (Davis Vantage > Pro1) and it was right on the money...so go figure.....some come out of > the factory A-ok and some don't!! > > de Bastos, Derek wrote: > > Trevor wrote: > > > > > >> The rain gauge has never been adjusted since the factory. > >> It required an adjustment of +12% to get from 84 tips of > >> the bucket (.01 in.per tip) to the 100 tips require to > >> measure 1" of water. > >> > > > > FWIW, I checked the calibration of my VP1 after changing its battery > > this past weekend. Like Trevor's, my rain gauge has not been adjusted > > since it left the factory. > > > > Coincidently (or not), I got a nearly identical result-- my gauge was > > reading low (81 tips for 1") and it took around two turns on the screws > > to fix it. Before reading this thread, I would have not suspected my > > gauge could be this far off. > > > > Derek > > CW2463 > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > ------------------------------ Message: 2 Date: Tue, 03 Jul 2007 11:37:28 -0700 From: Ken True Subject: Re: [wxqc] Davis Vantage Pro2 Rain Gauge Calibration To: Discussion of weather data quality issues Message-ID: <468A9768.8020906 at saratoga-weather.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed I haven't seen the adjustment for the tipping buckets mentioned in later ISS documentation, but the earlier separate rain collector II ( http://www.davisnet.com/product_documents/weather/manuals/rain_collector.pdf ) on page 11 shows a diagram of the adjustment screw. One turn clockwise will lower the reading by 6% while one turn anti-clockwise will raise the reading by 6%. Both screws have to be rotated in the same direction and the same amount to properly do the adjustment. So two anti-clockwise turns on both screws should raise the measurement by about 12%. I had compared my VP1 collector to a neighbors older VP1 and a manual 4" collector and found I needed to adjust the VP collector up by about 11% to match the readings. Now all three are within 0.01 (one tip) for a rain event. Ken True CW1792 http://saratoga-weather.org/ Victor Engel wrote: > I'm just waiting for it to stop raining so I can check mine . BTW, > until this thread started, I was unaware of an adjustment screw. I'm > going to have to pull out the manual to see where it's located. > > On 7/3/07, Trevor wrote: > >> It pays to check....I check another station that I run (Davis Vantage >> Pro1) and it was right on the money...so go figure.....some come out of >> the factory A-ok and some don't!! >> >> de Bastos, Derek wrote: >> >>> Trevor wrote: >>> >>> >>> >>>> The rain gauge has never been adjusted since the factory. >>>> It required an adjustment of +12% to get from 84 tips of >>>> the bucket (.01 in.per tip) to the 100 tips require to >>>> measure 1" of water. >>>> >>>> >>> FWIW, I checked the calibration of my VP1 after changing its battery >>> this past weekend. Like Trevor's, my rain gauge has not been adjusted >>> since it left the factory. >>> >>> Coincidently (or not), I got a nearly identical result-- my gauge was >>> reading low (81 tips for 1") and it took around two turns on the screws >>> to fix it. Before reading this thread, I would have not suspected my >>> gauge could be this far off. >>> >>> Derek >>> CW2463 >>> _______________________________________________ >>> wxqc mailing list >>> Post messages to wxqc at lists.gladstonefamily.net >>> To unsubcribe or change delivery options, please go to: >>> http://server.gladstonefamily.net/mailman/listinfo/wxqc >>> >>> The contents of this message are the responsibility of the author. >>> >>> >>> >> _______________________________________________ >> wxqc mailing list >> Post messages to wxqc at lists.gladstonefamily.net >> To unsubcribe or change delivery options, please go to: >> http://server.gladstonefamily.net/mailman/listinfo/wxqc >> >> The contents of this message are the responsibility of the author. >> >> > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > ------------------------------ Message: 3 Date: Tue, 3 Jul 2007 15:45:20 -0700 From: "Bryce Alexander" Subject: Re: [wxqc] Over reporting of rainfall by Wunderground To: "'Discussion of weather data quality issues'" Message-ID: <020f01c7bdc3$d8ee5980$03371e0a at Artemis> Content-Type: text/plain; charset="us-ascii" I use neither Davis, nor Wunderground, however I have many years of working on computers so I am going to take a shot. Wunderground simply takes what it gets. They do not post-process the data to try to convert it. They do however want the data in inches, not metric, so I would suspect that the problem is in your software. It is probably reporting the data to Wunderground as "normal parameters" (0.1in) for a tipping bucket and not making the conversion before sending the data off to Wunderground. I would bet that if you recalibrate your bucket to 0.25mm the data would then be correct, but then you still need to make the conversions for your local display. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of ashokmpatel at gujaratweather.com Sent: Monday, July 02, 2007 7:33 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Over reporting of rainfall by Wunderground Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Wunderground is reporting 223 mm, which is 25% more than what I have measured. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. ------------------------------ Message: 4 Date: Tue, 03 Jul 2007 16:36:37 -0700 From: lwood at mountainbase.com Subject: [wxqc] Davis Vantage Pro 2 Rain Gauge Calibration To: wxqc at lists.gladstonefamily.net Message-ID: <20070703163637.b014af6efb42cca08111bb1cc252e7a0.c4d833816b.wbe at email.secure server.net> Content-Type: TEXT/plain; CHARSET=US-ASCII Hi Victor The adjustment screws are located just below the tipping buckets. A counter clockwise turn raises the screw, restricting the downward movement of the bucket. This allows the buckets to tip with less accumulation. Shortening the screw, requires the bucket to travel farther and thus more weight on the opposite end to tip the bucket. Lance CW1020 ------------------------------ Message: 5 Date: Wed, 4 Jul 2007 11:04:31 -0500 From: "Erik Proseus" Subject: Re: [wxqc] Over reporting of rainfall by Wunderground To: "'Discussion of weather data quality issues'" Message-ID: <000001c7be55$0215f700$6800a8c0 at PROSEUSDESKTOP> Content-Type: text/plain; charset="us-ascii" Ashok, Just out of curiousity, have you installed the metric rain adapter that comes with the VP2 into your sensor suite? From the manual, "This adapter adds weight to the tipping mechanism, adjusting it to tip for every 0.2 mm of rainfall instead of every 0.01." --Erik -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bryce Alexander Sent: Tuesday, July 03, 2007 5:45 PM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Over reporting of rainfall by Wunderground I use neither Davis, nor Wunderground, however I have many years of working on computers so I am going to take a shot. Wunderground simply takes what it gets. They do not post-process the data to try to convert it. They do however want the data in inches, not metric, so I would suspect that the problem is in your software. It is probably reporting the data to Wunderground as "normal parameters" (0.1in) for a tipping bucket and not making the conversion before sending the data off to Wunderground. I would bet that if you recalibrate your bucket to 0.25mm the data would then be correct, but then you still need to make the conversions for your local display. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of ashokmpatel at gujaratweather.com Sent: Monday, July 02, 2007 7:33 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Over reporting of rainfall by Wunderground Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Wunderground is reporting 223 mm, which is 25% more than what I have measured. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. ------------------------------ Message: 6 Date: Wed, 4 Jul 2007 19:28:09 -0700 (PDT) From: Ashok Patel Subject: Re: [wxqc] Over reporting of rainfall by Wunderground To: webmaster at memphisweather.net, Discussion of weather data quality issues Message-ID: <216975.67749.qm at web51506.mail.re2.yahoo.com> Content-Type: text/plain; charset="iso-8859-1" Erik, Yes I have installed the metric adapter as per instructions in the Vantage Pro 2 manual. The problem is that as per my record, there was 177 mm. on July 2nd. 2007 which Wunderground is reporting as 224.8 mm. This is approx. 25 % more than my reading. Strangely, Wunderground is way out on 3rd. July for reporting rainfall of similar 224.8 mm. instead of 44.8 mm. recorded by me. Also my rainfall readings are comparable with that recorded in Rajkot city where my Weather Statiob is located. Ashok Patel CW8030 RingRoad Weather Station http://www.GujaratWeather.com Erik Proseus wrote: Ashok, Just out of curiousity, have you installed the metric rain adapter that comes with the VP2 into your sensor suite? From the manual, "This adapter adds weight to the tipping mechanism, adjusting it to tip for every 0.2 mm of rainfall instead of every 0.01." --Erik -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bryce Alexander Sent: Tuesday, July 03, 2007 5:45 PM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Over reporting of rainfall by Wunderground I use neither Davis, nor Wunderground, however I have many years of working on computers so I am going to take a shot. Wunderground simply takes what it gets. They do not post-process the data to try to convert it. They do however want the data in inches, not metric, so I would suspect that the problem is in your software. It is probably reporting the data to Wunderground as "normal parameters" (0.1in) for a tipping bucket and not making the conversion before sending the data off to Wunderground. I would bet that if you recalibrate your bucket to 0.25mm the data would then be correct, but then you still need to make the conversions for your local display. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of ashokmpatel at gujaratweather.com Sent: Monday, July 02, 2007 7:33 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Over reporting of rainfall by Wunderground Hi Gurus, I am uploading weather data to CWOP ID CW8030 and also to Weather Underground ID IGUJARAT6 . I am told that I am the only Weather Stations from India on CWOP. Recently Indian Monsoon season has started and Rajkot had 175.6 mm (approx. 7 Inches) of rain on 28th June. The rainfall data on Wunderground is showing 25% more than my data records on Vantage Pro 2 console as well as my website at http://www.GujaratWeather.com . My Vantage Pro 2 is calibrated to use metric units so one tip of rain bucket is 0.2 mm.,however, Wunderground is counting that as 0.25 mm or 0.01 inch. Wunderground is reporting 223 mm, which is 25% more than what I have measured. Could some experts guide me on this matter? Thanks Ashok Patel RingRoad Weather Station http://www.GujaratWeather.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. --------------------------------- Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070704/92968b a0/attachment.htm ------------------------------ _______________________________________________ wxqc mailing list Send messages to wxqc at lists.gladstonefamily.net To unsubscribe or change options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of these messages are the responsibility of the author(s). End of wxqc Digest, Vol 33, Issue 3 *********************************** From heathsmith at comcast.net Thu Jul 5 08:38:21 2007 From: heathsmith at comcast.net (Heath Smith) Date: Thu, 5 Jul 2007 09:38:21 -0400 Subject: [wxqc] Problem with monthly total rainfall on WU -- KCOCOLOR78 In-Reply-To: Message-ID: Rich, Looking over your data at WU, I picked out a day where WU reported 3+ inches last month. I then followed the link at the bottom to examine the comma delimited file at the bottom of the weather tables If you look at the data in the CSV, the parameter to the left of the VWS V13.01 is the daily rainfall total. That parameter reported by your software is what WU reports as the daily rainfall. WU does not for example use an accumulator to calculate daily rain, it simply accepts the last report of daily rainfall. So looking at yours, within 32 minutes, the total jumps from 0.31 inches to 2.98 inches. What is also interesting to note is that the hourly rainfall rate did not increase (steady at 0.02 inches during this same time frame). 2007-05-02 08:06:00,48.5,42.9,30.13,South,180,4,7,81,0.02,,---,0.31,VWS V13.01, 2007-05-02 08:32:00,48.7,43.1,30.13,SSE,158,5,5,81,0.02,,---,2.98,VWS V13.01, I suppose it is possible if you had extremely heavy rainfall, however the hourly rainfall would seem to contradict that possibility. Another couple possibilities are: 1) The La Crosse console rain total did increase 3 inches, maybe due to noise from some other source. That has been seen. To debug, wait for the next rainfall, examine whether or not the console's rain total parameter is indeed increasing beyond a reasonable amount. 2) The software received a bad rain total and ran with it. La Crosse units are notorious for reporting bad readings. If you run HeavyWeather along with VWS, this is very probable. What we can conclude is that the problem is not a WU error but rather a hardware (or more likely) a software problem #2. --- From: Rich Brunnworth Subject: [wxqc] Problem with monthly total rainfall on WU Sent: May 31 '07 01:38 I'm a bit confused, nothing abnormal for a newbie. My station is a LaCrosse 2310, uses Heavy weather to talk to the computer, uses VWS for display and upload to wunderground personal weather stations. OK...... here's the problem: The monthly total rainfall in HW and VWS shows as 6.7 some inches of rain, which is correct. Once the data is sent upstream to wunderground it gets set to 16. some inches of total rain for the month. I've noodled around with the history file of HW and can't see anything wrong which leads me to believe that VWS might be the problem. BUT... since the display on the computer reads correctly I don't think that there is anything wrong with the VWS database. I might be wrong tho. So just off the cuff I'm thinking that somehow weather underground is either multiplying my total somehow, or somewhere along the line the data being sent to WU isn't the database that I think it is. Any ideas what or where the problem might be? Rich This email scanned with AVG antivirus program KCOCOLOR78 --- From ibbrunnie at comcast.net Thu Jul 5 09:01:27 2007 From: ibbrunnie at comcast.net (Rich Brunnworth) Date: Thu, 05 Jul 2007 08:01:27 -0600 Subject: [wxqc] Problem with monthly total rainfall on WU -- KCOCOLOR78 In-Reply-To: References: Message-ID: <468CF9B7.7090703@comcast.net> I can't say that I've done anything different to any of the sensor wiring or to the console itself since I first saw the problem. What I have done is blow away the database and history file and let the software recreate both files. Since then everything is working as it should, so I guess there was an error in one of those files that was compounding itself. Regardless, now it is gone and I'll just keep an eye on it for the rest of the year. Thanks for taking a look and trying to figure out what went SNAFU. LOL Rich This email scanned with AVG antivirus program Heath Smith wrote: > Rich, > > Looking over your data at WU, I picked out a day where WU reported 3+ inches > last month. > > I then followed the link at the bottom to examine the comma delimited file > at the bottom of the weather tables > > If you look at the data in the CSV, the parameter to the left of the VWS > V13.01 is the daily rainfall total. > > That parameter reported by your software is what WU reports as the daily > rainfall. WU does not for example use an accumulator to calculate daily > rain, it simply accepts the last report of daily rainfall. > > So looking at yours, within 32 minutes, the total jumps from 0.31 inches to > 2.98 inches. > > What is also interesting to note is that the hourly rainfall rate did not > increase (steady at 0.02 inches during this same time frame). > > 2007-05-02 08:06:00,48.5,42.9,30.13,South,180,4,7,81,0.02,,---,0.31,VWS > V13.01, > 2007-05-02 08:32:00,48.7,43.1,30.13,SSE,158,5,5,81,0.02,,---,2.98,VWS > V13.01, > > I suppose it is possible if you had extremely heavy rainfall, however the > hourly rainfall would seem to contradict that possibility. > > Another couple possibilities are: > > 1) The La Crosse console rain total did increase 3 inches, maybe due to > noise from some other source. That has been seen. To debug, wait for the > next rainfall, examine whether or not the console's rain total parameter is > indeed increasing beyond a reasonable amount. > > 2) The software received a bad rain total and ran with it. La Crosse units > are notorious for reporting bad readings. If you run HeavyWeather along with > VWS, this is very probable. > > What we can conclude is that the problem is not a WU error but rather a > hardware (or more likely) a software problem #2. > > From t_biskit at yahoo.com Tue Jul 10 08:58:52 2007 From: t_biskit at yahoo.com (Thomas Hybiske) Date: Tue, 10 Jul 2007 06:58:52 -0700 (PDT) Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... Message-ID: <125067.40287.qm@web33109.mail.mud.yahoo.com> Yesterday morning right before the onset of a thunderstorm, my station experienced a >2mb pressure spike with a near vertical rise time. It lasted for only a few minutes before dropping and settling slight below where it was before the storm. I checked other stations in my area (which is rural and farily wide), and they too experienced the same spike. Can anyone provide an explanation for the event? Here's the URL to the event: http://www.findu.com/cgi-bin/wxpage.cgi?call=K3gm&last=48 Tom Hybiske, K3GM --------------------------------- Now that's room service! Choose from over 150,000 hotels in 45,000 destinations on Yahoo! Travel to find your fit. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070710/e166502e/attachment.htm From Russell.B.Chadwick at noaa.gov Tue Jul 10 11:36:14 2007 From: Russell.B.Chadwick at noaa.gov (Russ Chadwick) Date: Tue, 10 Jul 2007 10:36:14 -0600 Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... In-Reply-To: <125067.40287.qm@web33109.mail.mud.yahoo.com> Message-ID: <000501c7c310$6ee59060$c76e4b89@jedi> This may have been a gust front of cooler (heavier) air generated by the cooling effect of evaporation at higher levels within the thunderstorm. These gust fronts are a hazard to landing aircraft and have caused numerous accidents in the past. Russ -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Thomas Hybiske Sent: Tuesday, July 10, 2007 7:59 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... Yesterday morning right before the onset of a thunderstorm, my station experienced a >2mb pressure spike with a near vertical rise time. It lasted for only a few minutes before dropping and settling slight below where it was before the storm. I checked other stations in my area (which is rural and farily wide), and they too experienced the same spike. Can anyone provide an explanation for the event? Here's the URL to the event: http://www.findu.com/cgi-bin/wxpage.cgi?call=K3gm&last=48 Tom Hybiske, K3GM _____ Now that's room service! Choose from over 150,000 hotels in 45,000 destinations on Yahoo! Travel to find your fit. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070710/c53d1f33/attachment.htm From brillig at gmail.com Tue Jul 10 11:41:42 2007 From: brillig at gmail.com (Victor Engel) Date: Tue, 10 Jul 2007 11:41:42 -0500 Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... In-Reply-To: <000501c7c310$6ee59060$c76e4b89@jedi> References: <125067.40287.qm@web33109.mail.mud.yahoo.com> <000501c7c310$6ee59060$c76e4b89@jedi> Message-ID: Russ, That was my first thought, too, but I would expect a corresponding surge in windspeed data that doesn't seem to be present. Can you explain that? Victor On 7/10/07, Russ Chadwick wrote: > > > > > This may have been a gust front of cooler (heavier) air generated by the > cooling effect of evaporation at higher levels within the thunderstorm. > These gust fronts are a hazard to landing aircraft and have caused numerous > accidents in the past. > From brillig at gmail.com Tue Jul 10 11:49:23 2007 From: brillig at gmail.com (Victor Engel) Date: Tue, 10 Jul 2007 11:49:23 -0500 Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... In-Reply-To: References: <125067.40287.qm@web33109.mail.mud.yahoo.com> <000501c7c310$6ee59060$c76e4b89@jedi> Message-ID: I take it back (sort of). There is a surge in windspeed. The magnitude is just smaller than I expected. On 7/10/07, Victor Engel wrote: > Russ, > > That was my first thought, too, but I would expect a corresponding > surge in windspeed data that doesn't seem to be present. Can you > explain that? > > Victor > > On 7/10/07, Russ Chadwick wrote: > > > > > > > > > > This may have been a gust front of cooler (heavier) air generated by the > > cooling effect of evaporation at higher levels within the thunderstorm. > > These gust fronts are a hazard to landing aircraft and have caused numerous > > accidents in the past. > > > From Russell.B.Chadwick at noaa.gov Tue Jul 10 11:55:33 2007 From: Russell.B.Chadwick at noaa.gov (Russ Chadwick) Date: Tue, 10 Jul 2007 10:55:33 -0600 Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... In-Reply-To: Message-ID: <000f01c7c313$216105b0$c76e4b89@jedi> The evaporation at higher levels causes the heavy cooler air to descend and, depending on the geometry, a location directly under the descending air will experience a sharp change in vertical velocity and not much change in horizontal velocity. Our CWOP stations only measure horizontal velocity. Russ -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Victor Engel Sent: Tuesday, July 10, 2007 10:49 AM To: Discussion of weather data quality issues Subject: Re: [wxqc] Seeking explanation for steep pressure spike yesterday.... I take it back (sort of). There is a surge in windspeed. The magnitude is just smaller than I expected. On 7/10/07, Victor Engel wrote: > Russ, > > That was my first thought, too, but I would expect a corresponding > surge in windspeed data that doesn't seem to be present. Can you > explain that? > > Victor > > On 7/10/07, Russ Chadwick wrote: > > > > > > > > > > This may have been a gust front of cooler (heavier) air generated by the > > cooling effect of evaporation at higher levels within the thunderstorm. > > These gust fronts are a hazard to landing aircraft and have caused numerous > > accidents in the past. > > > _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From Webmaster at MemphisWeather.net Tue Jul 10 11:57:24 2007 From: Webmaster at MemphisWeather.net (=?iso-8859-1?Q?Erik=20Proseus?=) Date: Tue, 10 Jul 2007 11:57:24 -0500 Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... Message-ID: <20070710165724.4017.qmail@hoster902.com> I see a fair amount of gust frontal passages on my station where there is a slight rise (or spike) in pressure immediately behind the front with an accompanying increase in wind speed or directional shift. Because of the resolution you can have on these personal stations and their graphs, it's much easier to detect slight increases in pressure and wind that you can't see when looking at standard ASOS data. it's one of the reasons I find it so interesting to own a station. I've learned a lot about how weather works on a micro- to mesoscale since acquiring it! --Erik -------------------------------------------------------- Erik Proseus, Webmaster and Forecaster [LINK: http://www.MemphisWeather.Net] MemphisWeather.Net e-mail: [LINK: mailto:webmaster at MemphisWeather.Net] webmaster at MemphisWeather.Net WXLIVE! - Realtime weather conditions from Bartlett WXLIVE!-Severe Weather - watches and warnings delivered to your e-mail, cell phone, or PDA -------Original Message------- From: Victor Engel Subject: Re: [wxqc] Seeking explanation for steep pressure spike yesterday.... Sent: Jul 10 '07 11:49 I take it back (sort of). There is a surge in windspeed. The magnitude is just smaller than I expected. On 7/10/07, Victor Engel <[LINK: http://mbox.memphisweather.net/compose.php?to=brillig at gmail.com] brillig at gmail.com> wrote: > Russ, > > That was my first thought, too, but I would expect a corresponding > surge in windspeed data that doesn't seem to be present. Can you > explain that? > > Victor > > On 7/10/07, Russ Chadwick <[LINK: http://mbox.memphisweather.net/compose.php?to=Russell.B.Chadwick at noaa.gov] Russell.B.Chadwick at noaa.gov> wrote: > > > > > > > > > > This may have been a gust front of cooler (heavier) air generated by the > > cooling effect of evaporation at higher levels within the thunderstorm. > > These gust fronts are a hazard to landing aircraft and have caused numerous > > accidents in the past. > > > _______________________________________________ wxqc mailing list Post messages to [LINK: http://mbox.memphisweather.net/compose.php?to=wxqc at lists.gladstonefamily.net] wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: [LINK: http://server.gladstonefamily.net/mailman/listinfo/wxqc] http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070710/93e2bace/attachment-0001.htm From brillig at gmail.com Tue Jul 10 12:14:51 2007 From: brillig at gmail.com (Victor Engel) Date: Tue, 10 Jul 2007 12:14:51 -0500 Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... In-Reply-To: <000f01c7c313$216105b0$c76e4b89@jedi> References: <000f01c7c313$216105b0$c76e4b89@jedi> Message-ID: But I see the same pattern at several stations over a fairly wide area. I don't believe they all could be directly under the decending air. Furthermore, if you look at the radar, the whole weather system seems to be moving fairly rapidly from west to east. Could there be a layer at ground level that's insulating the weather stations from wind at higher levels? On 7/10/07, Russ Chadwick wrote: > The evaporation at higher levels causes the heavy cooler air to descend and, > depending on the geometry, a location directly under the descending air will > experience a sharp change in vertical velocity and not much change in > horizontal velocity. Our CWOP stations only measure horizontal velocity. > > Russ > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Victor Engel > Sent: Tuesday, July 10, 2007 10:49 AM > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Seeking explanation for steep pressure spike > yesterday.... > > I take it back (sort of). There is a surge in windspeed. The magnitude > is just smaller than I expected. > > On 7/10/07, Victor Engel wrote: > > Russ, > > > > That was my first thought, too, but I would expect a corresponding > > surge in windspeed data that doesn't seem to be present. Can you > > explain that? > > > > Victor > > > > On 7/10/07, Russ Chadwick wrote: > > > > > > > > > > > > > > > This may have been a gust front of cooler (heavier) air generated by the > > > cooling effect of evaporation at higher levels within the thunderstorm. > > > These gust fronts are a hazard to landing aircraft and have caused > numerous > > > accidents in the past. > > > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From dshelms at comcast.net Tue Jul 10 13:07:14 2007 From: dshelms at comcast.net (dshelms at comcast.net) Date: Tue, 10 Jul 2007 18:07:14 +0000 Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... Message-ID: <071020071807.26273.4693CAD00009B95C000066A122070208539C03040A089C0B@comcast.net> Hi All: I looked at stations as far away as 25 miles from Tom's station in central Mass, and all had a very nice 4-5 millibar pressure spike above the nominal baseline pressure. Ordinarily, I would except a significant wind gust with a pressure jump such as this, but the event occurred around 4AM local after a nocturnal radiation inversion has setup for the night (cooler at the surface and warming with height for 1,000 ft or so). My theory... Its possible the gravity wave (which was detected by the surface pressure jump everyone saw) originated hundreds of miles away to the west from a thunderstorm downrush and rode on the nearly frictionless surface of the nocturnal surface radiation inversion. The gravity wave did not cause enough turbulence in most cases to significantly increase the surface winds. Gravity/internal waves are very common in the atmosphere, and typically don't influence sensible "weather", but not always. Most numerical modelers consider internal waves (short wave length/high frequency) to be noise and try to filter them out. However, if we are going to predict short term weather (link thunderstorm initiation), we will need to detect, monitor, and predict the largest gravity waves in the future. This would be one motivation for CWOP/APRSWXNET moving from a 5 minute data collection cycle to a 1 minute data collection cycle. We are not considering making a change to observation upload frequency from 5 minutes at this time since the science of gravity wave prediction is not well developed. Dave CW0351 Tom's Station Time Series: http://www.findu.com/cgi-bin/wxpage.cgi?call=K3gm&last=48 Nearby Stations: http://www.findu.com/cgi-bin/wxnear.cgi?call=K3gm -------------- Original message ---------------------- From: "Victor Engel" > But I see the same pattern at several stations over a fairly wide > area. I don't believe they all could be directly under the decending > air. > > Furthermore, if you look at the radar, the whole weather system seems > to be moving fairly rapidly from west to east. Could there be a layer > at ground level that's insulating the weather stations from wind at > higher levels? > > On 7/10/07, Russ Chadwick wrote: > > The evaporation at higher levels causes the heavy cooler air to descend and, > > depending on the geometry, a location directly under the descending air will > > experience a sharp change in vertical velocity and not much change in > > horizontal velocity. Our CWOP stations only measure horizontal velocity. > > > > Russ > > > > -----Original Message----- > > From: wxqc-bounces at lists.gladstonefamily.net > > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Victor Engel > > Sent: Tuesday, July 10, 2007 10:49 AM > > To: Discussion of weather data quality issues > > Subject: Re: [wxqc] Seeking explanation for steep pressure spike > > yesterday.... > > > > I take it back (sort of). There is a surge in windspeed. The magnitude > > is just smaller than I expected. > > > > On 7/10/07, Victor Engel wrote: > > > Russ, > > > > > > That was my first thought, too, but I would expect a corresponding > > > surge in windspeed data that doesn't seem to be present. Can you > > > explain that? > > > > > > Victor > > > > > > On 7/10/07, Russ Chadwick wrote: > > > > > > > > > > > > > > > > > > > > This may have been a gust front of cooler (heavier) air generated by the > > > > cooling effect of evaporation at higher levels within the thunderstorm. > > > > These gust fronts are a hazard to landing aircraft and have caused > > numerous > > > > accidents in the past. > > > > > > > > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > > > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From t_biskit at yahoo.com Tue Jul 10 13:40:45 2007 From: t_biskit at yahoo.com (Thomas Hybiske) Date: Tue, 10 Jul 2007 11:40:45 -0700 (PDT) Subject: [wxqc] Seeking explanation for steep pressure spike yesterday.... In-Reply-To: <071020071807.26273.4693CAD00009B95C000066A122070208539C03040A089C0B@comcast.net> Message-ID: <319788.52149.qm@web33109.mail.mud.yahoo.com> Amazing explanation, Dave. Thanks! Tom, K3GM dshelms at comcast.net wrote: Hi All: I looked at stations as far away as 25 miles from Tom's station in central Mass, and all had a very nice 4-5 millibar pressure spike above the nominal baseline pressure. Ordinarily, I would except a significant wind gust with a pressure jump such as this, but the event occurred around 4AM local after a nocturnal radiation inversion has setup for the night (cooler at the surface and warming with height for 1,000 ft or so). My theory... Its possible the gravity wave (which was detected by the surface pressure jump everyone saw) originated hundreds of miles away to the west from a thunderstorm downrush and rode on the nearly frictionless surface of the nocturnal surface radiation inversion. The gravity wave did not cause enough turbulence in most cases to significantly increase the surface winds. Gravity/internal waves are very common in the atmosphere, and typically don't influence sensible "weather", but not always. Most numerical modelers consider internal waves (short wave length/high frequency) to be noise and try to filter them out. However, if we are going to predict short term weather (link thunderstorm initiation), we will need to detect, monitor, and predict the largest gravity waves in the future. This would be one motivation for CWOP/APRSWXNET moving from a 5 minute data collection cycle to a 1 minute data collection cycle. We are not considering making a change to observation upload frequency from 5 minutes at this time since the science of gravity wave prediction is not well developed. Dave CW0351 Tom's Station Time Series: http://www.findu.com/cgi-bin/wxpage.cgi?call=K3gm&last=48 Nearby Stations: http://www.findu.com/cgi-bin/wxnear.cgi?call=K3gm -------------- Original message ---------------------- From: "Victor Engel" > But I see the same pattern at several stations over a fairly wide > area. I don't believe they all could be directly under the decending > air. > > Furthermore, if you look at the radar, the whole weather system seems > to be moving fairly rapidly from west to east. Could there be a layer > at ground level that's insulating the weather stations from wind at > higher levels? > > On 7/10/07, Russ Chadwick wrote: > > The evaporation at higher levels causes the heavy cooler air to descend and, > > depending on the geometry, a location directly under the descending air will > > experience a sharp change in vertical velocity and not much change in > > horizontal velocity. Our CWOP stations only measure horizontal velocity. > > > > Russ > > > > -----Original Message----- > > From: wxqc-bounces at lists.gladstonefamily.net > > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Victor Engel > > Sent: Tuesday, July 10, 2007 10:49 AM > > To: Discussion of weather data quality issues > > Subject: Re: [wxqc] Seeking explanation for steep pressure spike > > yesterday.... > > > > I take it back (sort of). There is a surge in windspeed. The magnitude > > is just smaller than I expected. > > > > On 7/10/07, Victor Engel wrote: > > > Russ, > > > > > > That was my first thought, too, but I would expect a corresponding > > > surge in windspeed data that doesn't seem to be present. Can you > > > explain that? > > > > > > Victor > > > > > > On 7/10/07, Russ Chadwick wrote: > > > > > > > > > > > > > > > > > > > > This may have been a gust front of cooler (heavier) air generated by the > > > > cooling effect of evaporation at higher levels within the thunderstorm. > > > > These gust fronts are a hazard to landing aircraft and have caused > > numerous > > > > accidents in the past. > > > > > > > > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > > > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. --------------------------------- No need to miss a message. Get email on-the-go with Yahoo! Mail for Mobile. Get started. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070710/4dc58ead/attachment.htm From t_biskit at yahoo.com Tue Jul 10 13:56:11 2007 From: t_biskit at yahoo.com (Thomas Hybiske) Date: Tue, 10 Jul 2007 11:56:11 -0700 (PDT) Subject: [wxqc] Do Gravity Waves effect the E regiion of the ionosphere? In-Reply-To: <071020071807.26273.4693CAD00009B95C000066A122070208539C03040A089C0B@comcast.net> Message-ID: <437468.77999.qm@web33108.mail.mud.yahoo.com> This question is primarily directed at Dave Helms being that he answered my previous query regarding the pressure spike yesterday here in central New England. But all are welcome to comment. Yesterday, there was an sporadic E opening all along the northeast into the upper midwest. The opening supported communications up to 50MHz. So I got thinking if the two were coincidental or if gravity waves had any influence on the E layer and its seemingly magic ability to enhance LOS radio communication to at times, thousands of miles? Tom Hybiske, K3GM --------------------------------- Yahoo! oneSearch: Finally, mobile search that gives answers, not web links. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070710/02a42589/attachment.htm From dshelms at comcast.net Tue Jul 10 14:08:19 2007 From: dshelms at comcast.net (dshelms at comcast.net) Date: Tue, 10 Jul 2007 19:08:19 +0000 Subject: [wxqc] Do Gravity Waves effect the E regiion of the ionosphere? Message-ID: <071020071908.24901.4693D923000482FB0000614522007340769C03040A089C0B@comcast.net> Hi Tom, I don't know much about the E-layer (once had to identify the E and F layers on a strip chart and code a message for Space Command while at Cape Canaveral AFS). E-layers exist in the Ionosphere, between 90 km (55 miles) and 150 km (95 miles) above the ground, while most gravity waves are below 3 km (2 miles) above ground level. Could be the same thunderstorms who's downrush caused the gravity wave also who's electrical activity influenced the E-layer generation? http://www.nature.com/nature/journal/v435/n7043/abs/nature03638.html Cause and effect relationships (or not) are interesting! Dave CW0351 -------------- Original message ---------------------- From: Thomas Hybiske > This question is primarily directed at Dave Helms being that he answered my > previous query regarding the pressure spike yesterday here in central New > England. But all are welcome to comment. Yesterday, there was an sporadic E > opening all along the northeast into the upper midwest. The opening supported > communications up to 50MHz. So I got thinking if the two were coincidental or > if gravity waves had any influence on the E layer and its seemingly magic > ability to enhance LOS radio communication to at times, thousands of miles? > > Tom Hybiske, K3GM > > > --------------------------------- Yahoo! oneSearch: Finally, mobile search that gives answers, not web links. -------------- next part -------------- An embedded message was scrubbed... From: Thomas Hybiske Subject: [wxqc] Do Gravity Waves effect the E regiion of the ionosphere? Date: Tue, 10 Jul 2007 18:56:34 +0000 Size: 2759 Url: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070710/dfdc3884/attachment-0001.eml From brillig at gmail.com Tue Jul 10 14:10:03 2007 From: brillig at gmail.com (Victor Engel) Date: Tue, 10 Jul 2007 14:10:03 -0500 Subject: [wxqc] Fwd: Seeking explanation for steep pressure spike yesterday.... In-Reply-To: References: <071020071807.26273.4693CAD00009B95C000066A122070208539C03040A089C0B@comcast.net> Message-ID: Oops. I meant to send to the group. ---------- Forwarded message ---------- > Hi All: > > I looked at stations as far away as 25 miles from Tom's station in central Mass, and all had a very nice 4-5 millibar pressure spike above the nominal baseline pressure. Ordinarily, I would except a significant wind gust with a pressure jump such as this, but the event occurred around 4AM local after a nocturnal radiation inversion has setup for the night (cooler at the surface and warming with height for 1,000 ft or so). > > My theory... Its possible the gravity wave (which was detected by the surface pressure jump everyone saw) originated hundreds of miles away to the west from a thunderstorm downrush and rode on the nearly frictionless surface of the nocturnal surface radiation inversion. The gravity wave did not cause enough turbulence in most cases to significantly increase the surface winds. But did you check the radar? There was a strong storm that passed by at the same time. I think the sharp change in pressure corresponds to the leading edge of the storm. Would you say the storm was being triggered by the gravity wave? What was the jetstream doing around that time? From dshelms at comcast.net Tue Jul 10 14:15:23 2007 From: dshelms at comcast.net (dshelms at comcast.net) Date: Tue, 10 Jul 2007 19:15:23 +0000 Subject: [wxqc] Fwd: Seeking explanation for steep pressure spike yesterday.... Message-ID: <071020071915.2306.4693DACB000D93540000090222064244139C03040A089C0B@comcast.net> Hi Victor, I'm flying blind on the origins of the gravity wave as I don't have access to "old" radar. Could be the thunderstorm you saw formed on the old gravity wave? Dave CW0351 -------------- Original message ---------------------- From: "Victor Engel" > Oops. I meant to send to the group. > > ---------- Forwarded message ---------- > > Hi All: > > > > I looked at stations as far away as 25 miles from Tom's station in central > Mass, and all had a very nice 4-5 millibar pressure spike above the nominal > baseline pressure. Ordinarily, I would except a significant wind gust with a > pressure jump such as this, but the event occurred around 4AM local after a > nocturnal radiation inversion has setup for the night (cooler at the surface and > warming with height for 1,000 ft or so). > > > > My theory... Its possible the gravity wave (which was detected by the surface > pressure jump everyone saw) originated hundreds of miles away to the west from a > thunderstorm downrush and rode on the nearly frictionless surface of the > nocturnal surface radiation inversion. The gravity wave did not cause enough > turbulence in most cases to significantly increase the surface winds. > > But did you check the radar? There was a strong storm that passed by > at the same time. I think the sharp change in pressure corresponds to > the leading edge of the storm. Would you say the storm was being > triggered by the gravity wave? What was the jetstream doing around > that time? > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From dshelms at comcast.net Tue Jul 10 14:20:26 2007 From: dshelms at comcast.net (dshelms at comcast.net) Date: Tue, 10 Jul 2007 19:20:26 +0000 Subject: [wxqc] Do Gravity Waves effect the E regiion of the ionosphere? Message-ID: <071020071920.10837.4693DBFA000D3F9C00002A5522064244139C03040A089C0B@comcast.net> Interesting enough, we used to try to document "vertical" lightning (e.g. sprites) from the Space Shuttle payload bay cameras while the Shuttle was on the dark side of the Earth. Every now and again we would capture a lightning flash that extended vertically above the thunderstorm anvil into the stratosphere and beyond. Very cool. Dave CW0351 -------------- Original message ---------------------- From: dshelms at comcast.net > Hi Tom, > > I don't know much about the E-layer (once had to identify the E and F layers on > a strip chart and code a message for Space Command while at Cape Canaveral AFS). > E-layers exist in the Ionosphere, between 90 km (55 miles) and 150 km (95 miles) > above the ground, while most gravity waves are below 3 km (2 miles) above ground > level. > > Could be the same thunderstorms who's downrush caused the gravity wave also > who's electrical activity influenced the E-layer generation? > http://www.nature.com/nature/journal/v435/n7043/abs/nature03638.html > > > Cause and effect relationships (or not) are interesting! > > Dave > CW0351 > > > -------------- Original message ---------------------- > From: Thomas Hybiske > > This question is primarily directed at Dave Helms being that he answered my > > previous query regarding the pressure spike yesterday here in central New > > England. But all are welcome to comment. Yesterday, there was an sporadic E > > opening all along the northeast into the upper midwest. The opening supported > > communications up to 50MHz. So I got thinking if the two were coincidental or > > if gravity waves had any influence on the E layer and its seemingly magic > > ability to enhance LOS radio communication to at times, thousands of miles? > > > > Tom Hybiske, K3GM > > > > > > --------------------------------- > Yahoo! oneSearch: Finally, mobile search that gives answers, not web links. > -------------- next part -------------- An embedded message was scrubbed... From: dshelms at comcast.net Subject: Re: [wxqc] Do Gravity Waves effect the E regiion of the ionosphere? Date: Tue, 10 Jul 2007 19:08:46 +0000 Size: 3697 Url: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070710/970d4569/attachment.eml From brillig at gmail.com Tue Jul 10 14:27:27 2007 From: brillig at gmail.com (Victor Engel) Date: Tue, 10 Jul 2007 14:27:27 -0500 Subject: [wxqc] Fwd: Seeking explanation for steep pressure spike yesterday.... In-Reply-To: <071020071915.2306.4693DACB000D93540000090222064244139C03040A089C0B@comcast.net> References: <071020071915.2306.4693DACB000D93540000090222064244139C03040A089C0B@comcast.net> Message-ID: The old radar I use is available on weatherunderground.com. Just enter a city (Salem, MA works for the purposes of this thread), click on the map, then at the bottom, look for a radar archive dialogue where you can select historical radar by date. You will get an animated radar for the day, with frames 30 minutes apart. Victor On 7/10/07, dshelms at comcast.net wrote: > Hi Victor, > > I'm flying blind on the origins of the gravity wave as I don't have access to "old" radar. Could be the thunderstorm you saw formed on the old gravity wave? > > Dave > CW0351 > > -------------- Original message ---------------------- > From: "Victor Engel" > > Oops. I meant to send to the group. > > > > ---------- Forwarded message ---------- > > > Hi All: > > > > > > I looked at stations as far away as 25 miles from Tom's station in central > > Mass, and all had a very nice 4-5 millibar pressure spike above the nominal > > baseline pressure. Ordinarily, I would except a significant wind gust with a > > pressure jump such as this, but the event occurred around 4AM local after a > > nocturnal radiation inversion has setup for the night (cooler at the surface and > > warming with height for 1,000 ft or so). > > > > > > My theory... Its possible the gravity wave (which was detected by the surface > > pressure jump everyone saw) originated hundreds of miles away to the west from a > > thunderstorm downrush and rode on the nearly frictionless surface of the > > nocturnal surface radiation inversion. The gravity wave did not cause enough > > turbulence in most cases to significantly increase the surface winds. > > > > But did you check the radar? There was a strong storm that passed by > > at the same time. I think the sharp change in pressure corresponds to > > the leading edge of the storm. Would you say the storm was being > > triggered by the gravity wave? What was the jetstream doing around > > that time? > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > From dshelms at comcast.net Tue Jul 10 15:34:50 2007 From: dshelms at comcast.net (dshelms at comcast.net) Date: Tue, 10 Jul 2007 20:34:50 +0000 Subject: [wxqc] Fwd: Seeking explanation for steep pressure spike yesterday.... Message-ID: <071020072034.14237.4693ED6A00000DD10000379D22064244139C03040A089C0B@comcast.net> Ok.. the peak pressure observed by Tom's weather station (K3GM) was on July 9th, at 13:15 UTC (09:15 local). The Taunton (BOX) radar shows a "mature" bow echo (very large arc'd line of thunderstorms) moving southeast through central Mass at this time: http://vortex.plymouth.edu/gen_nids.cgi?ident=BOX&pl=n0r&yy=2007&mm=07&dd=09&hh=13&nn=15&size=912x684&loop=no&zoom=¢er= This same bow echo was evident at 08:30 UTC over north/central NY on the Burlington (CXX) radar: http://vortex.plymouth.edu/gen_nids.cgi?ident=cxx&pl=n0r&yy=2007&mm=07&dd=09&hh=08&nn=30&size=912x684&loop=no&zoom=¢er= Finally, the stormed that generated the downrush which begat the gravity wave/bow echo appears to have originated from an intense thunderstorm north of Toronto around 03:00 UTC, as seen on the Buffalo (BUF) radar. http://vortex.plymouth.edu/gen_nids.cgi?ident=buf&pl=n0r&yy=2007&mm=07&dd=09&hh=03&nn=30&size=912x684&loop=no&zoom=¢er= So, the thunderstorms forming on the bow echo over central Mass are the grandsons/daughters of the seminal Canadian storm. The Central US has these variety of nocturnal southeast moving thunderstorms in the summer as the storms move around upper high pressure. In severe cases, these bow echoes are called "Derechos". More on Derechos: http://www.spc.noaa.gov/misc/AbtDerechos/derechofacts.htm Dave CW0351 Radar images from the PSU NIDS Archive: http://vortex.plymouth.edu/nids.html -------------- Original message ---------------------- From: "Victor Engel" > The old radar I use is available on weatherunderground.com. Just enter > a city (Salem, MA works for the purposes of this thread), click on the > map, then at the bottom, look for a radar archive dialogue where you > can select historical radar by date. You will get an animated radar > for the day, with frames 30 minutes apart. > > Victor > > On 7/10/07, dshelms at comcast.net wrote: > > Hi Victor, > > > > I'm flying blind on the origins of the gravity wave as I don't have access to > "old" radar. Could be the thunderstorm you saw formed on the old gravity wave? > > > > Dave > > CW0351 > > > > -------------- Original message ---------------------- > > From: "Victor Engel" > > > Oops. I meant to send to the group. > > > > > > ---------- Forwarded message ---------- > > > > Hi All: > > > > > > > > I looked at stations as far away as 25 miles from Tom's station in central > > > Mass, and all had a very nice 4-5 millibar pressure spike above the nominal > > > baseline pressure. Ordinarily, I would except a significant wind gust with > a > > > pressure jump such as this, but the event occurred around 4AM local after a > > > nocturnal radiation inversion has setup for the night (cooler at the surface > and > > > warming with height for 1,000 ft or so). > > > > > > > > My theory... Its possible the gravity wave (which was detected by the > surface > > > pressure jump everyone saw) originated hundreds of miles away to the west > from a > > > thunderstorm downrush and rode on the nearly frictionless surface of the > > > nocturnal surface radiation inversion. The gravity wave did not cause > enough > > > turbulence in most cases to significantly increase the surface winds. > > > > > > But did you check the radar? There was a strong storm that passed by > > > at the same time. I think the sharp change in pressure corresponds to > > > the leading edge of the storm. Would you say the storm was being > > > triggered by the gravity wave? What was the jetstream doing around > > > that time? > > > _______________________________________________ > > > wxqc mailing list > > > Post messages to wxqc at lists.gladstonefamily.net > > > To unsubcribe or change delivery options, please go to: > > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > > > The contents of this message are the responsibility of the author. > > > > From kn4lf at earthlink.net Tue Jul 10 17:13:16 2007 From: kn4lf at earthlink.net (Thomas Giella KN4LF) Date: Tue, 10 Jul 2007 18:13:16 -0400 Subject: [wxqc] Do Gravity Waves effect the E regiion of the ionosphere? Message-ID: <001701c7c33f$84586510$6701a8c0@thomas> Tom yes very much so. Check out my radiowave propagation website at http://www.kn4lf.com/kn4lf8.htm . Take Care, Thomas Giella, KN4LF Retired Meteorologist Lakeland, FL, USA kn4lf at earthlink.net Harmful Man Induced Climate Change (Global Warming) Refuted: http://www.kn4lf.com/globalwarminglie.htm Lakeland, Florida Daily Climatological Weather Data Archive: http://www.kn4lf.com/kn4lf22.htm Lakeland, Florida Real Time Weather Observations: http://www.kn4lf.com/index1.html FL & US Raw Weather Forecasting Resource Links: http://www.kn4lf.com/kn4lf13.htm Date: Tue, 10 Jul 2007 11:56:11 -0700 (PDT) From: Thomas Hybiske Subject: [wxqc] Do Gravity Waves effect the E regiion of the ionosphere? To: wxqc at lists.gladstonefamily.net Message-ID: <437468.77999.qm at web33108.mail.mud.yahoo.com> Content-Type: text/plain; charset="iso-8859-1" This question is primarily directed at Dave Helms being that he answered my previous query regarding the pressure spike yesterday here in central New England. But all are welcome to comment. Yesterday, there was an sporadic E opening all along the northeast into the upper midwest. The opening supported communications up to 50MHz. So I got thinking if the two were coincidental or if gravity waves had any influence on the E layer and its seemingly magic ability to enhance LOS radio communication to at times, thousands of miles? Tom Hybiske, K3GM From bryce at azlab.net Tue Jul 10 18:26:55 2007 From: bryce at azlab.net (Bryce Alexander) Date: Tue, 10 Jul 2007 16:26:55 -0700 Subject: [wxqc] Fwd: Seeking explanation for steep pressure spikeyesterday.... In-Reply-To: <071020072034.14237.4693ED6A00000DD10000379D22064244139C03040A089C0B@comcast.net> Message-ID: <024e01c7c349$d1bcaaa0$03371e0a@Artemis> The Derecho explanation sounds an awful lot like a Haboob of the deserts. I would like to know if there really is a difference or are we giving two names to the same type of event? I do know that the most obvious difference is the wall of dust in a Haboob, but setting that aside what other differences are there? -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of dshelms at comcast.net Sent: Tuesday, July 10, 2007 1:35 PM To: Victor Engel Cc: Discussion of weather data quality issues Subject: Re: [wxqc] Fwd: Seeking explanation for steep pressure spikeyesterday.... Ok.. the peak pressure observed by Tom's weather station (K3GM) was on July 9th, at 13:15 UTC (09:15 local). The Taunton (BOX) radar shows a "mature" bow echo (very large arc'd line of thunderstorms) moving southeast through central Mass at this time: http://vortex.plymouth.edu/gen_nids.cgi?ident=BOX&pl=n0r&yy=2007&mm=07&dd=09 &hh=13&nn=15&size=912x684&loop=no&zoom=¢er= This same bow echo was evident at 08:30 UTC over north/central NY on the Burlington (CXX) radar: http://vortex.plymouth.edu/gen_nids.cgi?ident=cxx&pl=n0r&yy=2007&mm=07&dd=09 &hh=08&nn=30&size=912x684&loop=no&zoom=¢er= Finally, the stormed that generated the downrush which begat the gravity wave/bow echo appears to have originated from an intense thunderstorm north of Toronto around 03:00 UTC, as seen on the Buffalo (BUF) radar. http://vortex.plymouth.edu/gen_nids.cgi?ident=buf&pl=n0r&yy=2007&mm=07&dd=09 &hh=03&nn=30&size=912x684&loop=no&zoom=¢er= So, the thunderstorms forming on the bow echo over central Mass are the grandsons/daughters of the seminal Canadian storm. The Central US has these variety of nocturnal southeast moving thunderstorms in the summer as the storms move around upper high pressure. In severe cases, these bow echoes are called "Derechos". More on Derechos: http://www.spc.noaa.gov/misc/AbtDerechos/derechofacts.htm Dave CW0351 Radar images from the PSU NIDS Archive: http://vortex.plymouth.edu/nids.html -------------- Original message ---------------------- From: "Victor Engel" > The old radar I use is available on weatherunderground.com. Just enter > a city (Salem, MA works for the purposes of this thread), click on the > map, then at the bottom, look for a radar archive dialogue where you > can select historical radar by date. You will get an animated radar > for the day, with frames 30 minutes apart. > > Victor > > On 7/10/07, dshelms at comcast.net wrote: > > Hi Victor, > > > > I'm flying blind on the origins of the gravity wave as I don't have access to > "old" radar. Could be the thunderstorm you saw formed on the old gravity wave? > > > > Dave > > CW0351 > > > > -------------- Original message ---------------------- > > From: "Victor Engel" > > > Oops. I meant to send to the group. > > > > > > ---------- Forwarded message ---------- > > > > Hi All: > > > > > > > > I looked at stations as far away as 25 miles from Tom's station in central > > > Mass, and all had a very nice 4-5 millibar pressure spike above the nominal > > > baseline pressure. Ordinarily, I would except a significant wind gust with > a > > > pressure jump such as this, but the event occurred around 4AM local after a > > > nocturnal radiation inversion has setup for the night (cooler at the surface > and > > > warming with height for 1,000 ft or so). > > > > > > > > My theory... Its possible the gravity wave (which was detected by the > surface > > > pressure jump everyone saw) originated hundreds of miles away to the west > from a > > > thunderstorm downrush and rode on the nearly frictionless surface of the > > > nocturnal surface radiation inversion. The gravity wave did not cause > enough > > > turbulence in most cases to significantly increase the surface winds. > > > > > > But did you check the radar? There was a strong storm that passed by > > > at the same time. I think the sharp change in pressure corresponds to > > > the leading edge of the storm. Would you say the storm was being > > > triggered by the gravity wave? What was the jetstream doing around > > > that time? > > > _______________________________________________ > > > wxqc mailing list > > > Post messages to wxqc at lists.gladstonefamily.net > > > To unsubcribe or change delivery options, please go to: > > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > > > The contents of this message are the responsibility of the author. > > > > _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From dshelms at comcast.net Wed Jul 11 07:43:39 2007 From: dshelms at comcast.net (Dave Helms) Date: Wed, 11 Jul 2007 08:43:39 -0400 Subject: [wxqc] Fwd: Seeking explanation for steep pressure spikeyesterday.... In-Reply-To: <024e01c7c349$d1bcaaa0$03371e0a@Artemis> References: <024e01c7c349$d1bcaaa0$03371e0a@Artemis> Message-ID: <4694D07B.6000308@comcast.net> Hi Bryce, Derecho are a very specific type of long-lived thunderstorm type and genesis. The origins/initiative of a Haboob and Derecho are similar, a downrush and resulting out-flow boundary. In my mind, if someone said, 'hey, look at the Haboob' I would see a roiling ball of dust and sand and not necessarily the parent thunderstorm (a Haboob can exist long after the thunderstorm that generated it has dissipated). So, Haboob describes how sand and dust are lifted and transported in a desert environment, while a Derecho describes how a class of thunderstorm forms and sustains itself. In either case, I would expect a weather station to measure a pressure jump with the passage of the Haboob or Dececho. Dave CW0351 Bryce Alexander wrote: >The Derecho explanation sounds an awful lot like a Haboob of the deserts. I >would like to know if there really is a difference or are we giving two >names to the same type of event? I do know that the most obvious difference >is the wall of dust in a Haboob, but setting that aside what other >differences are there? > >-----Original Message----- >From: wxqc-bounces at lists.gladstonefamily.net >[mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of >dshelms at comcast.net >Sent: Tuesday, July 10, 2007 1:35 PM >To: Victor Engel >Cc: Discussion of weather data quality issues >Subject: Re: [wxqc] Fwd: Seeking explanation for steep pressure >spikeyesterday.... > >Ok.. the peak pressure observed by Tom's weather station (K3GM) was on July >9th, at 13:15 UTC (09:15 local). > >The Taunton (BOX) radar shows a "mature" bow echo (very large arc'd line of >thunderstorms) moving southeast through central Mass at this time: >http://vortex.plymouth.edu/gen_nids.cgi?ident=BOX&pl=n0r&yy=2007&mm=07&dd=09 >&hh=13&nn=15&size=912x684&loop=no&zoom=¢er= > >This same bow echo was evident at 08:30 UTC over north/central NY on the >Burlington (CXX) radar: >http://vortex.plymouth.edu/gen_nids.cgi?ident=cxx&pl=n0r&yy=2007&mm=07&dd=09 >&hh=08&nn=30&size=912x684&loop=no&zoom=¢er= > >Finally, the stormed that generated the downrush which begat the gravity >wave/bow echo appears to have originated from an intense thunderstorm north >of Toronto around 03:00 UTC, as seen on the Buffalo (BUF) radar. >http://vortex.plymouth.edu/gen_nids.cgi?ident=buf&pl=n0r&yy=2007&mm=07&dd=09 >&hh=03&nn=30&size=912x684&loop=no&zoom=¢er= > >So, the thunderstorms forming on the bow echo over central Mass are the >grandsons/daughters of the seminal Canadian storm. The Central US has these >variety of nocturnal southeast moving thunderstorms in the summer as the >storms move around upper high pressure. In severe cases, these bow echoes >are called "Derechos". More on Derechos: >http://www.spc.noaa.gov/misc/AbtDerechos/derechofacts.htm > > > >Dave >CW0351 > >Radar images from the PSU NIDS Archive: >http://vortex.plymouth.edu/nids.html > > > > -------------- Original message ---------------------- >From: "Victor Engel" > > >>The old radar I use is available on weatherunderground.com. Just enter >>a city (Salem, MA works for the purposes of this thread), click on the >>map, then at the bottom, look for a radar archive dialogue where you >>can select historical radar by date. You will get an animated radar >>for the day, with frames 30 minutes apart. >> >>Victor >> >>On 7/10/07, dshelms at comcast.net wrote: >> >> >>>Hi Victor, >>> >>>I'm flying blind on the origins of the gravity wave as I don't have >>> >>> >access to > > >>"old" radar. Could be the thunderstorm you saw formed on the old gravity >> >> >wave? > > >>>Dave >>>CW0351 >>> >>> -------------- Original message ---------------------- >>>From: "Victor Engel" >>> >>> >>>>Oops. I meant to send to the group. >>>> >>>>---------- Forwarded message ---------- >>>> >>>> >>>>>Hi All: >>>>> >>>>>I looked at stations as far away as 25 miles from Tom's station in >>>>> >>>>> >central > > >>>>Mass, and all had a very nice 4-5 millibar pressure spike above the >>>> >>>> >nominal > > >>>>baseline pressure. Ordinarily, I would except a significant wind gust >>>> >>>> >with > > >>a >> >> >>>>pressure jump such as this, but the event occurred around 4AM local >>>> >>>> >after a > > >>>>nocturnal radiation inversion has setup for the night (cooler at the >>>> >>>> >surface > > >>and >> >> >>>>warming with height for 1,000 ft or so). >>>> >>>> >>>>>My theory... Its possible the gravity wave (which was detected by >>>>> >>>>> >the > > >>surface >> >> >>>>pressure jump everyone saw) originated hundreds of miles away to the >>>> >>>> >west > > >>from a >> >> >>>>thunderstorm downrush and rode on the nearly frictionless surface of >>>> >>>> >the > > >>>>nocturnal surface radiation inversion. The gravity wave did not cause >>>> >>>> > > > >>enough >> >> >>>>turbulence in most cases to significantly increase the surface winds. >>>> >>>>But did you check the radar? There was a strong storm that passed by >>>>at the same time. I think the sharp change in pressure corresponds to >>>>the leading edge of the storm. Would you say the storm was being >>>>triggered by the gravity wave? What was the jetstream doing around >>>>that time? >>>>_______________________________________________ >>>>wxqc mailing list >>>>Post messages to wxqc at lists.gladstonefamily.net >>>>To unsubcribe or change delivery options, please go to: >>>>http://server.gladstonefamily.net/mailman/listinfo/wxqc >>>> >>>>The contents of this message are the responsibility of the author. >>>> >>>> >>> >>> > >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > > > > From cwop at adobe-labs.com Wed Jul 11 20:34:33 2007 From: cwop at adobe-labs.com (Brent Gordon) Date: Wed, 11 Jul 2007 19:34:33 -0600 Subject: [wxqc] Radar Secondary Echo? Message-ID: <46958529.8060704@adobe-labs.com> An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070711/5ba08f4b/attachment-0001.htm -------------- next part -------------- A non-text attachment was scrubbed... Name: WeatherRadar.jpg Type: image/jpeg Size: 100451 bytes Desc: not available Url : http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070711/5ba08f4b/attachment-0001.jpg From ibbrunnie at comcast.net Thu Jul 12 06:54:54 2007 From: ibbrunnie at comcast.net (Rich Brunnworth) Date: Thu, 12 Jul 2007 05:54:54 -0600 Subject: [wxqc] Radar Secondary Echo? In-Reply-To: <46958529.8060704@adobe-labs.com> References: <46958529.8060704@adobe-labs.com> Message-ID: <4696168E.8000107@comcast.net> I believe that it is an outflow boundary. Basically a cool front that develops in front of a storm. Rich This email scanned with AVG antivirus program Brent Gordon wrote: > This is probably off-topic, but I'm sure someone here knows the > answer. In the image below, there is a blue line just west of the > highway from Santa Fe to Albuquerque, then circling out to the west. > I'm guessing this is an echo from something off screen. Is this > correct and what causes it? I've seen this before on the Albuquerque > radar, with the line moving with the radar update. > From stsander at sblan.net Thu Jul 12 07:35:28 2007 From: stsander at sblan.net (Stan Sander) Date: Thu, 12 Jul 2007 06:35:28 -0600 Subject: [wxqc] Radar Secondary Echo? In-Reply-To: <4696168E.8000107@comcast.net> References: <46958529.8060704@adobe-labs.com> <4696168E.8000107@comcast.net> Message-ID: <46962010.9090800@sblan.net> Rich Brunnworth wrote: > I believe that it is an outflow boundary. Basically a cool front that > develops in front of a storm. > > Rich I'll agree with Rich. I've seen these many times before and all the data that I can correlate with it suggests that it is an outflow boundary from thunderstorms. Sometimes these storms are very distant, at least in our case here in NM. In the case of the image you posted, if you had taken a look at the composite reflectivity image you could see the storms that generated this boundary. They aren't visible in the base reflectivity image because the radar is "blinded" by the Sandia mountains. Another interesting observation as I was looking at this briefly last night as it was occurring, this very outflow boundary that you posted spawned additional thunderstorms along and just in front of it shortly after the t