From bweybrecht at bellsouth.net Fri Jul 1 16:42:13 2005 From: bweybrecht at bellsouth.net (Bob) Date: Fri Jul 1 16:42:22 2005 Subject: [wxqc] calibrating a rain gauge In-Reply-To: <42C400A0.2030403@bridgesinn.com> Message-ID: <000001c57e7d$5cb8bdb0$0a02a8c0@wsr88d> If it's the standard, 4 inch Oregon Scientific unit, SLOWLY pouring the following amount of water through it, should give the listed results. 1 qt = 4.74in rain = 120.49mm rain 1 cup = 1.19in rain = 30.12mm rain -----Original Message----- From: wxqc-bounces@lists.gladstonefamily.net [mailto:wxqc-bounces@lists.gladstonefamily.net] On Behalf Of John Mulhollen Sent: Thursday, June 30, 2005 10:25 AM To: wxqc@lists.gladstonefamily.net Subject: [wxqc] calibrating a rain gauge Without meaning to open up a can of worms (tm), what's the best way to calibrate a rain gauge? i'm thinking mine is a "bit off", as the recent rains here dumped about 3 inches into my 33 gallon trash can (with nearly vertical sides, set in the middle of the yard, much to my wife's dismay); the rain gauge registered 9mm. i'm using an oregon scientific wm918 weather system with all the stock equipment (but i added about 150 feet of category 6 cable between the sensors and the display unit). thanks! John Mulhollen CWOP1401 http://bridgesinn.com/weather/wx.htm Weather@BridgesInn.com _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From cjfasciano at comcast.net Fri Jul 1 16:16:58 2005 From: cjfasciano at comcast.net (Christopher J. Fasciano) Date: Fri Jul 1 16:50:41 2005 Subject: [wxqc] made the news...correction Message-ID: <070120052016.20668.42C5A4BA0009C1CB000050BC220076106401020E070C9C0E00060C@comcast.net> Friends: I wanted to wait til we had some break in action to report minor wind damage here. We also had a wind gust of 22mph (whoopee) on a 10' pole that is raised a few feet so its up about 12-13' at most. Rain about 0.35" fell. No hail was seen. Peak rain fall rate was 2.80" by the way also. -- Christopher J. Fasciano; Latitude: 40.32N | Longitude: 79.76W, Elevation: 309 meters (1015 feet) North Huntingdon, Twp. aka Irwin, PA in the subdivion of: Circleville/Senaca Valley, in Westmoreland County Weather handles: CW2172/KPANORTH4 Dear Chris, Thanks so much for the email with the damage report. It's always good to hear from the viewers. Sincerely, Don Schwenneker WTAE Staff Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050701/fdd94166/attachment.html From cjfasciano at comcast.net Fri Jul 1 16:31:10 2005 From: cjfasciano at comcast.net (Christopher J. Fasciano) Date: Fri Jul 1 16:50:41 2005 Subject: [wxqc] update Message-ID: <070120052031.16036.42C5A80E0000560800003EA4220076143801020E070C9C0E00060C@comcast.net> up date to the update...after showing my family the e-mail, they said we had nice branches in our yard. I would assume safely and saying medium size branches fell. Sorry for any inconvience. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050701/f90536d8/attachment.html From george at prevelige.com Sat Jul 2 10:22:32 2005 From: george at prevelige.com (George Prevelige) Date: Sat Jul 2 10:23:18 2005 Subject: [wxqc] WeatherLink Script In-Reply-To: <200507011600.j61G0N1h028576@ns-mr6.netsolmail.com> Message-ID: <200507021423.j62ENCH9020261@ms-smtp-01-eri0.texas.rr.com> WeatherLink 5.6 adds more CWOP friendly data to its APRS upload report. However, in order for these data to be transferred, a current status window (Bulletin, Summary...) must be open. The problem: sometimes I have to restart my server remotely. I placed a shortcut of WeatherLink into my startup folder, which automatically launches WL upon reboot. But, there is no way to automatically open a current status window. Solution: I created a very simple script that sends the proper key command to WeatherLink to open the Bulletin window. I placed this script in the startup folder with the WL shortcut and the problem is solved. If anyone on this list would be interested in this script, just drop me a line and I will email it to you. Thanks, George ___________________________________ george@prevelige.com From w0lta at 4dv.net Sat Jul 2 14:30:29 2005 From: w0lta at 4dv.net (Rick Patterson) Date: Sat Jul 2 14:31:02 2005 Subject: [wxqc] WeatherLink Script Message-ID: Hi George, What an eligent solution. Please send me a copy of your script. Thanks, Rick w0lta >------- Original Message ------- >From : George Prevelige[mailto:george@prevelige.com] >Sent : 7/2/2005 8:22:32 AM >To : wxqc@lists.gladstonefamily.net >Cc : >Subject : RE : [wxqc] WeatherLink Script > > WeatherLink 5.6 adds more CWOP friendly data to its APRS upload report. >However, in order for these data to be transferred, a current status window >(Bulletin, Summary...) must be open. > >The problem: sometimes I have to restart my server remotely. I placed a >shortcut of WeatherLink into my startup folder, which automatically launches >WL upon reboot. But, there is no way to automatically open a current status >window. > >Solution: I created a very simple script that sends the proper key command >to WeatherLink to open the Bulletin window. I placed this script in the >startup folder with the WL shortcut and the problem is solved. > >If anyone on this list would be interested in this script, just drop me a >line and I will email it to you. > >Thanks, >George >___________________________________ >george@prevelige.com > >_______________________________________________ >wxqc mailing list >wxqc@lists.gladstonefamily.net >http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. From leaning_r at hotmail.com Sat Jul 2 22:18:31 2005 From: leaning_r at hotmail.com (Randall Richmond) Date: Sat Jul 2 22:18:36 2005 Subject: [wxqc] WeatherLink Script In-Reply-To: <200507021423.j62ENCH9020261@ms-smtp-01-eri0.texas.rr.com> Message-ID: Hello George: Please send me a copy of the script. Regards Randall >From: "George Prevelige" >Reply-To: Discussion of data quality issues > >To: >Subject: [wxqc] WeatherLink Script >Date: Sat, 2 Jul 2005 09:22:32 -0500 >MIME-Version: 1.0 >Received: from charon.gladstonefamily.net ([24.63.236.128]) by >mc3-f30.hotmail.com with Microsoft SMTPSVC(6.0.3790.211); Sat, 2 Jul 2005 >07:24:02 -0700 >Received: (qmail 29072 invoked by uid 10008); 2 Jul 2005 14:23:21 -0000 >Received: from localhost (HELO charon.gladstonefamily.net) (127.0.0.1) by >charon.gladstonefamily.net (qpsmtpd/0.27-dev) with ESMTP; Sat, 02 Jul 2005 >10:23:21 -0400 >Received: (qmail 29058 invoked by uid 10008); 2 Jul 2005 14:23:17 -0000 >Received: neutral (charon.gladstonefamily.net: local policy) >Received: from ms-smtp-01.texas.rr.com (HELO >ms-smtp-01-eri0.texas.rr.com)(24.93.47.40)by charon.gladstonefamily.net >(qpsmtpd/0.27-dev) with ESMTP;Sat, 02 Jul 2005 10:23:17 -0400 >Received: from junior (cpe-66-68-4-180.austin.res.rr.com [66.68.4.180])by >ms-smtp-01-eri0.texas.rr.com (8.12.10/8.12.7) with ESMTP idj62ENCH9020261 >for ;Sat, 2 Jul 2005 09:23:12 -0500 (CDT) >X-Message-Info: JGTYoYF78jHDbEfAUuEUOCgs6m20Iu2nUZfoPcu54+E= >Return-Path: >Delivered-To: mailman-wxqc@lists.gladstonefamily.net >X-Mailer: Microsoft Office Outlook, Build 11.0.6353 >X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 >Thread-Index: AcV+Vf9FBcmCdgteTjGr7z4rQ6xWIAAudg+w >X-Virus-Scanned: Symantec AntiVirus Scan Engine >X-BeenThere: wxqc@lists.gladstonefamily.net >X-Mailman-Version: 2.1.5 >Precedence: list >List-Id: Discussion of data quality issues >List-Unsubscribe: >, > >List-Archive: >List-Post: >List-Help: >List-Subscribe: >, > >Errors-To: wxqc-bounces@lists.gladstonefamily.net >X-OriginalArrivalTime: 02 Jul 2005 14:24:02.0095 (UTC) >FILETIME=[B19CEBF0:01C57F11] > > WeatherLink 5.6 adds more CWOP friendly data to its APRS upload report. >However, in order for these data to be transferred, a current status window >(Bulletin, Summary...) must be open. > >The problem: sometimes I have to restart my server remotely. I placed a >shortcut of WeatherLink into my startup folder, which automatically >launches >WL upon reboot. But, there is no way to automatically open a current status >window. > >Solution: I created a very simple script that sends the proper key command >to WeatherLink to open the Bulletin window. I placed this script in the >startup folder with the WL shortcut and the problem is solved. > >If anyone on this list would be interested in this script, just drop me a >line and I will email it to you. > >Thanks, >George >___________________________________ >george@prevelige.com > >_______________________________________________ >wxqc mailing list >wxqc@lists.gladstonefamily.net >http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. From mayswl at comcast.net Sun Jul 3 01:31:29 2005 From: mayswl at comcast.net (William Mays) Date: Sun Jul 3 01:31:39 2005 Subject: [wxqc] Over-Range Humidity data Message-ID: <5usec1hivf0uh9tl5tgnnn5j43uaqvfq7k@4ax.com> Hello; I am CW2671. Is there a fix known for use with the Oregon Scientific WM-918 and FreeWX software to avoid the huge jump in Dew Point when the data reaches 100%RH and goes into Over-Range? That appears to be the cause of an apparent drop of ~60F in dew point. Recently, I have set the FreeWX parameter Offset: OHum=+6.1 in an attempt to improve calibration. The benefit is not yet proven, might this be an issue for the reported data indicating >100%RH? Are the units of OHum offset known? (dew point F, C; %RH?, grains of H2O per ton of air?) Relocation and shielding of the T & H sensor has improved the Temp data over the last week or so. Thanks; Bill -- Bill Mays Cinnaminson, NJ 08077 NEW EMAIL: mayswl@comcast.net OLD: mayswl@uscom.com Texas: AH-HS'61, UT-Austin'66; Moorestown, NJ: RCA, GE, MM, Lockheed Martin From clayj at nwlink.com Sun Jul 10 01:58:47 2005 From: clayj at nwlink.com (Clay Jackson) Date: Sun Jul 10 01:58:57 2005 Subject: [wxqc] Davis Humidity Issue In-Reply-To: <002201c57779$0a8fc6b0$628a3243@MARKSCOMPAQ> References: <200506220853343.SM00652@markamd2003> <002201c57779$0a8fc6b0$628a3243@MARKSCOMPAQ> Message-ID: I've got a Davis WMII - and the humidity sensor has started acting up. It's consistently reading about 5% high, which translates to a dew point error of several degrees - outside the QC range. The sensor is about 6' AGL on a mast that's about 15' from the side of our house; on a Davis platform/shield. The mast sits in the middle of a garden that currently only has a few rose bushes in it and is NOT overly watered (drip system); and in fact it's had no 'extra' water used this season (we're averaging just under 1" of rain/ week here outside Seattle. The nearest foliage is about 8' from the base of the sensor shield, so I don't THINK that should make a difference. I'm going to go out tomorrow and dismount and clean the sensor (compressed air blast). Anyone got any ideas other than that? I suppose I could "hook" my recording program (meteo) to subtract 5% from the RH, but that's kind of a drag.... Clay Jackson From James.Dudley at noaa.gov Sun Jul 10 20:34:59 2005 From: James.Dudley at noaa.gov (James Dudley) Date: Sun Jul 10 20:34:42 2005 Subject: [wxqc] Davis Humidity Issue Message-ID: Clay, I too have had issues with my trusty old WMII, where the relative humidity will "behave" for a long period of time and then seemingly either jump up or down by a few percent and then stay "stuck" at this new level of callibration. I did take my temp/rh sensor apart and clean it out however the readings didn't change. I just gave up and "adjusted" the calibration on the Davis unit to read back to the old level. The unit has been behaving nicely at its new calibration level. Still don't know why the calibration changed in the first place? Jim Dudley CW2553 Hanford CA ----- Original Message ----- From: Clay Jackson Date: Saturday, July 9, 2005 10:58 pm Subject: [wxqc] Davis Humidity Issue > I've got a Davis WMII - and the humidity sensor has started acting > > up. It's consistently reading about 5% high, which translates to > a > dew point error of several degrees - outside the QC range. > > The sensor is about 6' AGL on a mast that's about 15' from the > side > of our house; on a Davis platform/shield. The mast sits in the > middle of a garden that currently only has a few rose bushes in it > > and is NOT overly watered (drip system); and in fact it's had no > 'extra' water used this season (we're averaging just under 1" of > rain/ > week here outside Seattle. The nearest foliage is about 8' from > the > base of the sensor shield, so I don't THINK that should make a > difference. > > I'm going to go out tomorrow and dismount and clean the sensor > (compressed air blast). > > Anyone got any ideas other than that? > > I suppose I could "hook" my recording program (meteo) to subtract > 5% > from the RH, but that's kind of a drag.... > > Clay Jackson > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From tbarstow at earthlink.net Mon Jul 11 13:02:19 2005 From: tbarstow at earthlink.net (Thomas Barstow) Date: Mon Jul 11 13:03:08 2005 Subject: [wxqc] VWS P45 Message-ID: <6.2.0.14.0.20050711130045.01dea348@pop.earthlink.net> I'm looking for VWS P45 the entire program. If you have it can you send it to me or tell me were I can get it. Second choice is the template from P45 if you can send that. Thank You www.moyockweather.com moyockweather@earthlink.net From gary.oldham at adelphia.net Mon Jul 11 13:16:59 2005 From: gary.oldham at adelphia.net (Gary Oldham) Date: Mon Jul 11 13:17:03 2005 Subject: [wxqc] VWS P45 Message-ID: <18907613.1121102219889.JavaMail.root@web8.mail.adelphia.net> An answer to your posting on the VWS Forum was posted with a link where you can download p45. gary.oldham(at)adelphia.net ---- Thomas Barstow wrote: ============= I'm looking for VWS P45 the entire program. If you have it can you send it to me or tell me were I can get it. Second choice is the template from P45 if you can send that. Thank You www.moyockweather.com moyockweather@earthlink.net _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From philip at gladstonefamily.net Fri Jul 15 10:56:07 2005 From: philip at gladstonefamily.net (Philip Gladstone) Date: Fri Jul 15 10:56:25 2005 Subject: [wxqc] Re: A comment on the data quality for the last two days In-Reply-To: <000b01c5894b$6a6e4050$6501a8c0@scott> References: <20050715010519.12657.qmail@charon.gladstonefamily.net> <000b01c5894b$6a6e4050$6501a8c0@scott> Message-ID: <42D7CE87.1080001@gladstonefamily.net> Scott, Yes, your data is almost certainly correct. Very small scale events do not show up in the analysis. I have noticed that my (personal) barometer readings are sometimes flagged when a sharp front moves through. Having said that, it would be nice if MADIS could somehow not flag these events. Actually, now I look more closely at your output, I see that MADIS flagged 7 readings, yet my script reported on 13 samples. Hmm -- that feels like a bug to me! I'll take a look. Philip Scott Pride wrote: > Philip, > I stand by my data as both days we had localized intense > thunderstorms producing large amounts of rain in short periods of time > and the corresponding rapid and steep decline in temp.. C3282, located > 8 miles NE from me, had similar rain amounts from the same storm on the > 13th and experienced a similar drop in temp during the same period. On > the 14th I watched the cell popup about 4 miles SW of me on radar, build > into a small but intense storm and then dissipate 4 miles NE of me > before reaching C3282 location. As this is typical summer weather for > the Lowcountry of South Carolina I expect I'll receive more data error > reports for the next two months as the data quality program can not take > into account these localized weather events. > > Scott Pride > > > ----- Original Message ----- > > *From:* Weather Quality > *To:* woodpro@hargray.com > *Sent:* Thursday, July 14, 2005 9:05 PM > *Subject:* Weather data quality report for 2005-07-14 > > Date UTC SITE Alt (mb) Temp ?F DewPt ?F Wind Dir Speed knts > 14-JUL-2005 1916 CW3308 1013.7 +0.35 *80* *+7.42* 74 > +3.43 0 +137 0.0 +4.5 > 14-JUL-2005 1931 CW3308 1014.3 -0.25 *78* *+9.42* 75 > +2.60 0 +137 0.0 +4.5 > 14-JUL-2005 1946 CW3308 1014.2 -0.15 *78* *+9.42* 76 > +1.62 0 +137 0.0 +4.5 > 14-JUL-2005 2001 CW3308 1014.3 -0.42 *77* *+7.99* 75 > +1.62 0 +114 0.0 +2.4 > 14-JUL-2005 2016 CW3308 1014.3 -0.42 *76* *+8.99* 74 > +3.25 0 +114 0.0 +2.4 > 14-JUL-2005 2031 CW3308 1014.8 -0.92 *74* *+10.99* 72 > +4.91 63 +75 1.7 +0.7 > 14-JUL-2005 2051 CW3308 1013.8 +0.08 *73* *+11.99* 72 > +4.66 0 +114 0.0 +2.4 > 14-JUL-2005 2101 CW3308 1013.9 -0.17 *74* *+6.31* 73 > +2.96 0 +119 0.0 +3.6 > 14-JUL-2005 2130 CW3308 1013.3 +0.43 *74* *+6.05* 74 > +2.66 0 +119 0.0 +3.6 > 14-JUL-2005 2150 CW3308 1013.2 +0.53 *75* *+6.33* 75 > +1.66 0 +119 0.0 +3.6 > 14-JUL-2005 2205 CW3308 1013.3 +0.09 *75* *+6.51* 75 > +1.95 0 +115 0.0 +4.6 > 14-JUL-2005 2220 CW3308 1013.4 -0.01 *76* *+6.11* 76 > +0.95 0 +115 0.0 +4.6 > 14-JUL-2005 2230 CW3308 1013.4 -0.01 *76* *+6.03* 76 > +0.95 0 +115 0.0 +4.6 > 14-JUL-2005 Errs CW3308 0/91 7/91 0/91 0/91 0/91 > 14-JUL-2005 Smry CW3308 +0.2 0.40 +3 2.50 +0 1.74 -21 > 146 +2.5 1.1 > > Note that times are in UTC. The values displayed are 'Observed > Error' The error value is 'analysis - observed'. I.e. if your > observed value is higher than the computed value, then the error > will be negative. The error readings are listed in *bold*. The row > with the time of 'Smry' is a daily summary and the data is 'mean > standard-deviation' for each observation during that day. The 'Errs' > row contains the number of samples in error / the number of samples > (as seen by MADIS). This may indicate more observations that are > shown above. This is due to the differing limits used by this > reporting program and the MADIS program itself. > > For more information: > > * Daily graph > . > > * Quality checking information . > * WXQC Mailing list > . > > To stop this email, just click here > > -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3322 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050715/78e363fa/smime.bin From dshelms at comcast.net Fri Jul 15 13:23:15 2005 From: dshelms at comcast.net (dshelms@comcast.net) Date: Fri Jul 15 13:23:19 2005 Subject: [wxqc] Re: A comment on the data quality for the last two days Message-ID: <071520051723.11988.42D7F1030001BA8100002ED422058844849C03040A089C0B@comcast.net> Hi Scott, MADIS provides us with an overall trend on a station's performance based on a series of observations (days and weeks). As you point out, MADIS QC info should not be interpreted to imply that a particular observation is "bad." MADIS QCMS flags alerts mesonet end-users (NOAA) of stations that additional assessment by data users who make the final determination of observation quality for a given observation. For MADIS, there needs to be a balance between efficiency (speed) and absolute accuracy of the QC info MADIS creates. MADIS' goal is primarily focused on helping operational meteorologists filter large volumes of observations so they can make real-time decisions about the behavior of the atmosphere. We use the MADIS QCMS data in a different manner, to help maintain our weather stations. Unfortunately, MADIS cannot be tuned to be absolute authority on QC of specific observations because of its primary mission of providing quick "triage" assessment of thousands of observations for NWS operations. I suggest ignoring individual QCMS flags and focus on the 14 week running QC statistics that Philip creates from MADIS information (green checks are good!). Hope this helps, Dave CW0351 > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > The contents of this message are the responsibility of the author. -------------- next part -------------- An embedded message was scrubbed... From: Philip Gladstone Subject: [wxqc] Re: A comment on the data quality for the last two days Date: Fri, 15 Jul 2005 14:56:44 +0000 Size: 9883 Url: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050715/bb850ee6/attachment.mht From pirkle at texoma.net Fri Jul 15 21:15:09 2005 From: pirkle at texoma.net (Rex Pirkle) Date: Sun Jul 17 21:22:40 2005 Subject: [wxqc] Discussion of data quality issues - Wind data standard? Davis WL5.6beta In-Reply-To: <200507151600.j6FG0AY01470@xlate1.mailsvcs.arrl.net> Message-ID: <000001c589a3$d005e910$0100a8c0@DJSSJ661> I've been using the Davis WeatherLink 5.6 beta software for couple of weeks, and found a couple significant APRS 'data quality' issues that might explain some of the discrepancies in 'Wind' QC error flagging. There may be a problem with the WeatherLink method of reporting 'Wind Direction', and the 'time stamp' of the data. The Davis Vantage Pro2 station memory/hardware has the ability to report three 'Wind Direction' parameters: 1) - 'Current' Wind Direction Resolution : 1 degree Range: 0 to 360 deg, Nominal Accuracy: +/- 7 deg. The Vantage Pro2 transmitter sends a new data packet to the console every 2? seconds. 2) Direction of High Wind Speed Compass Rose, Resolution: 22.5 deg Direction code of the High Wind speed. 0 = N, 1 = NNE, 2 = NE, 14= NW, 15 = NNW, 255 = Dashed 3) Prevailing or Dominant Wind Direction Compass Rose, Resolution: 22.5 deg Direction code of the Dominant Wind. 0 = N, 1 = NNE, 2 = NE, 14 = NW, 15 = NNW, 255 = Dashed The Davis APRS string reports only the 'Current' Wind Direction. I presently have my station set to upload an APRS every 5 mins. In that cycle about 120 'Wind' samples are made. The Davis APRS string reports only 1 out of 120 of these data points; it is a 'snapshot' of the single data reading prior to the data upload. Should not the preference in a "NOAA Standard" be the 'Dominant Wind Direction' report? It seems to me that would be much more valuable information than three isolated data points in a 15-minute period. The 'Current Wind' data reported now has too few samples to be statistically significant. The APRS protocol is ambiguous about which 'wind direction' data is appropriate, so what is most correct for CWOP purposes? If 'Prevailing Wind' is preferred, over what interval? 10-mins? To report 'Prevailing Wind' on APRS, the 'Compass Rose' data would require translation to a numerical heading in degrees, and would be limited to +/- 22.5 deg resolution. Davis stations use a 'bit-bucket' method to determine the prevailing wind direction, and stores only the most frequent 'Compass Rose' heading in the sample interval. The WL5.5 and WL5.6Beta software also time-stamp the APRS data packets incorrectly. The time-stamp in the Davis APRS string is the time when Telnet upload initiates, not the time that last sample took place. Depending on the weather station log interval, and upload time offsets in 'Internet Settings', the packets may be miss-marked by several minutes. So, what is an 'acceptable' time window for transmitting the data? Why all the questions? -- WL5.6beta does not support radio transmission of APRS, so I'm trying to develop a simple utility that will read the Davis archive weather log and produce a APRS string usable by the UI-View32 'Weather Station' feature. The goal is to correct the Davis APRS report errors and include 10 minute wind gust, and also 1 hr and 24 hr rain data. Radio transmission will be much more reliable than relying on my lousy dial-up Internet connection for the data feed. RF is the first choice for APRS data, not the last. Rex Pirkle K8CYJ-5/AR863 From sam at wa4phy.net Sun Jul 17 21:55:47 2005 From: sam at wa4phy.net (Sam Drinkard) Date: Sun Jul 17 21:55:50 2005 Subject: [wxqc] Madis or something else? Message-ID: <42DB0C23.3070805@wa4phy.net> Just checked the MADIS surface display page, and it's showing me with alt of 1068.3 / 31.55" ! Wow.. after seeing that, I had to look at other places including the VWSAPRS info that was to be sent, and it's showing 1019.9, just as the console is showing. Where in the world did such strange numbers come from? Other APRSWXNET stations appear to be reporting mostly correct info. Did something burp somewhere a few hours back? Looking at the log, it appears that the erroneous data was there even at 1334Z and forward. Don't know how far back that goes... Anybody else seeing strange ALT numbers? -- Snowman From pirkle at texoma.net Mon Jul 18 00:23:37 2005 From: pirkle at texoma.net (Rex Pirkle) Date: Mon Jul 18 00:20:43 2005 Subject: [wxqc] Madis or something else? Message-ID: <000501c58b50$788f9f10$0100a8c0@DJSSJ661> Snowman, You are seeing the data from AR704 (KC5DDG). That station is so close to you (1 mile away) that it displayed instead of yours on the MADIS map. You have to 'zoom in' to see both stations. I have the same problem viewing MADIS surface display with KGYI, 1 mile from my location. Rex - K8CYJ - AR863 The data in question: AR704 (APRSWXNET) KC5DDG Martinez GA US time slp t / td dir / spd / gst/pcp presWx & skyCover (UTC) (mb) (F) (mph) (in.) 0319 1068.3(Q) 81.0(V)/75.70(V) 202?(V)/000(V)/000/0.00" 0304 1068.3(Q) 81.0(V)/75.70(V) 202?(V)/000(V)/000/0.00" 0249 1068.3(Q) 81.0(V)/74.60(V) 202?(V)/000(V)/000/0.00" 0234 1068.3(Q) 82.0(V)/74.80(V) 202?(V)/000(V)/000/0.00" 0219 1068.3(Q) 82.0(V)/74.40(V) 202?(V)/000(V)/000/0.00" 0204 1068.3(Q) 82.0(V)/74.40(V) 202?(V)/000(V)/000/0.00" 0149 1068.3(Q) 83.0(V)/75.00(V) 202?(V)/000(V)/000/0.00" 0134 1068.3(Q) 83.0(V)/74.20(V) 202?(V)/000(V)/000/0.00" 0119 1068.3(Q) 84.0(V)/74.80(V) 202?(V)/000(V)/000/0.00" ************************* Just checked the MADIS surface display page, and it's showing me with alt of 1068.3 / 31.55" ! Wow.. after seeing that, I had to look at other places including the VWSAPRS info that was to be sent, and it's showing 1019.9, just as the console is showing. Where in the world did such strange numbers come from? Other APRSWXNET stations appear to be reporting mostly correct info. Did something burp somewhere a few hours back? Looking at the log, it appears that the erroneous data was there even at 1334Z and forward. Don't know how far back that goes... Anybody else seeing strange ALT numbers? -- Snowman From sam at wa4phy.net Mon Jul 18 12:05:36 2005 From: sam at wa4phy.net (Sam Drinkard) Date: Mon Jul 18 12:05:37 2005 Subject: [wxqc] Madis or something else? In-Reply-To: <000501c58b50$788f9f10$0100a8c0@DJSSJ661> References: <000501c58b50$788f9f10$0100a8c0@DJSSJ661> Message-ID: <42DBD350.2050002@wa4phy.net> Hi Rex, Hmmm... I did not even look at that, as his station plot had been separated from mine by a good 1/4" or so, but I see now, if I slide the ball to close separation, I show up. Wonder how he got moved to essentially on top of me. In fact, after zooming in further, he is in the wrong place. According to the map now, his station lies to my SE, when in fact, he is NW of me by about 3 or 4 miles. For the longest, his station was not even showing up on the madis surface page. Somehow his location has gotten screwed up. He definately has some calibration problems, as well as elevation problems according to Philip's info pages. Perhaps if Dave reads this, he can make the adjustment back where it is supposed to be ... Thanks for the heads up! Sam -- Snowman From rmichl at charter.net Mon Jul 18 12:59:15 2005 From: rmichl at charter.net (rmichl@charter.net) Date: Mon Jul 18 12:59:16 2005 Subject: [wxqc] (no subject) Message-ID: <44abkh$11qtnl6@mxip02a.cluster1.charter.net> plase remove me from e-mail list From dshelms at comcast.net Mon Jul 18 22:09:23 2005 From: dshelms at comcast.net (Dave Helms) Date: Mon Jul 18 22:09:14 2005 Subject: [wxqc] Madis or something else? In-Reply-To: <42DBD350.2050002@wa4phy.net> References: <000501c58b50$788f9f10$0100a8c0@DJSSJ661> <42DBD350.2050002@wa4phy.net> Message-ID: <42DC60D3.4050003@comcast.net> Hi Sam, Are you talking about this station: http://www.findu.com/cgi-bin/wxpage.cgi?call=KC5DDG His location in the CWOP database is: http://www.findu.com/cgi-bin/find.cgi?call=KC5DDG Latitude: 33.49833 Longitude: -82.125 ---this is south of Columbia Road (GA 232) From QRZ.com, his location is here: 131 W LYNNE DR MARTINEZ, GA 30907 http://maps.google.com/maps?q=131+West+LYNNE+Drive,+MARTINEZ,+GA+30907&spn=0.274661,0.481407&hl=en 33.512202,-82.126236 --- this us just north of Columbia Road (GA 232) The difference is less than a mile, and should not make a big difference in the weather data as the elevation appears to be about the same. Dave Sam Drinkard wrote: > Hi Rex, > > Hmmm... I did not even look at that, as his station plot had been > separated from mine by a good 1/4" or so, but I see now, if I slide > the ball to close separation, I show up. Wonder how he got moved to > essentially on top of me. In fact, after zooming in further, he is in > the wrong place. According to the map now, his station lies to my SE, > when in fact, he is NW of me by about 3 or 4 miles. For the longest, > his station was not even showing up on the madis surface page. > Somehow his location has gotten screwed up. He definately has some > calibration problems, as well as elevation problems according to > Philip's info pages. Perhaps if Dave reads this, he can make the > adjustment back where it is supposed to be ... > Thanks for the heads up! > > Sam > From sam at wa4phy.net Tue Jul 19 09:35:09 2005 From: sam at wa4phy.net (Sam Drinkard) Date: Tue Jul 19 09:35:11 2005 Subject: [wxqc] Madis or something else? In-Reply-To: <42DC60D3.4050003@comcast.net> References: <000501c58b50$788f9f10$0100a8c0@DJSSJ661> <42DBD350.2050002@wa4phy.net> <42DC60D3.4050003@comcast.net> Message-ID: <42DD018D.4040805@wa4phy.net> Hi Dave, Yes, that's the station. I drove down to in front of his house and got the coordinates and sent them to Russ. His location is shown on the map as being on the S. side of Columbia road, but in fact, he is on the N. side of Columbia road, approx .7 mile from me. Elevation wise, you are correct.. about the same as me. What had me confused was his station was covering me up on the madis surface display, and I didn't realize that till somebody pointed that out. I had just assumed it was me..... Then I thought it was the station in Evans, but he's not even showing up lately. At any rate, his coordinates according to the gps are N33.51121 / W082.12540. -- Snowman From t_biskit at yahoo.com Tue Jul 19 20:57:53 2005 From: t_biskit at yahoo.com (Thomas Hybiske) Date: Tue Jul 19 20:57:53 2005 Subject: [wxqc] Problem with Weatherlink 5.5 and Com Port Message-ID: <20050720005753.34539.qmail@web52713.mail.yahoo.com> I'm not sure if brought this on myself by foolin' with the com settings, and I'm not sure how to fix it. Thought maybe someone could offer a suggestion. Running Windows XP, if I reboot the PC, or if there's a power failure with abrupt termination, then re-launch Weatherlink, it dumps out of the upload with the following error in the log "Weatherlink tried to open a comport that is in use by another program. Please wait for the other program to finish, or close the other program." I have to disable the com port, rebott the PC, and enable the com port in order for it to hook up again. Is there something I'm doing wrong, or is this how it works. Tnx, Tom Hybiske, K3GM --------------------------------- Start your day with Yahoo! - make it your home page -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050719/0eade31b/attachment.html From mark at markwyman.com Tue Jul 19 21:32:22 2005 From: mark at markwyman.com (Mark W) Date: Tue Jul 19 21:33:31 2005 Subject: [wxqc] Problem with Weatherlink 5.5 and Com Port References: <20050720005753.34539.qmail@web52713.mail.yahoo.com> Message-ID: <000d01c58cca$e0b15e50$628a3243@MARKSCOMPAQ> No, something is wrong with your XP installation. Two things to check: Look for spyware or autodialer software (intended to be nasty). So use a spyware removal tool and virus scanner to check yourself out. Then look in your startup folder for auto-running programs and make sure there is nothing in there that could use the COM port. Perhaps an old instance of Weatherlink that crashes on startup and then keeps hold of the port. If in the worst case, you can check the RUN keys in the registry for any nasties or whoopsies there. -Mark ----- Original Message ----- From: Thomas Hybiske To: wxqc@lists.gladstonefamily.net Sent: Tuesday, July 19, 2005 8:57 PM Subject: [wxqc] Problem with Weatherlink 5.5 and Com Port I'm not sure if brought this on myself by foolin' with the com settings, and I'm not sure how to fix it. Thought maybe someone could offer a suggestion. Running Windows XP, if I reboot the PC, or if there's a power failure with abrupt termination, then re-launch Weatherlink, it dumps out of the upload with the following error in the log "Weatherlink tried to open a comport that is in use by another program. Please wait for the other program to finish, or close the other program." I have to disable the com port, rebott the PC, and enable the com port in order for it to hook up again. Is there something I'm doing wrong, or is this how it works. Tnx, Tom Hybiske, K3GM ------------------------------------------------------------------------------ Start your day with Yahoo! - make it your home page ------------------------------------------------------------------------------ _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050719/daa85917/attachment.html From pirkle at texoma.net Tue Jul 19 23:40:11 2005 From: pirkle at texoma.net (Rex Pirkle) Date: Tue Jul 19 23:40:22 2005 Subject: [wxqc] Problem with Weatherlink 5.5 and Com Port Message-ID: <000001c58cdc$bc8df1c0$0100a8c0@DJSSJ661> Tom, If your system died in a power failure, run scandisk first to make sure you do not have any disk errors, WL5.5 might be reading a corrupted file. Then check to see if you have created a conflict on your COM port: START>PROGRAMS>ACCESSORIES>SYSTEM TOOLS>SYSTEM INFORMATION Check through the 'Hardware Resource" summaries, 'Conflicts/Sharing', IRQ's etc. to see that the 'Status' checks are all 'OK'. Davis docs for Vantage Pro 2 say," The console uses a serial or USB port... If you are connecting the console directly to the computer, leave the setting at 19200, the highest rate for the port. Vantage Pro2 supports baud rates of 1200,2400, 4800, 9600, 14400, 19200" If you do not 'auto detect' the Com port in WL5.5 set-up, you will have to match the baud rate of you com port setting. Party-data-stop should be N-8-1. >From the Desktop, RIGHT-click 'My Computer', select 'Properties', then 'Device Manager'. Check under "Mice and other pointing devices' and "Modems", making sure that XP didn't slip in a device driver that doesn't belong there. These are serial devices and XP will sometimes auto-install an incorrect device driver there, creating a conflict. If you see something wrong, either 'Uninstall' or 'Disable' it. My guess is that this is the likely problem. By disable/re-boot/enable sequence, you deny XP the chance to slip its own conflicting device driver in at start-up. It cannot load it because you disabled the port. Check the windows startup log to look for clues. On my machine, XP is convinced that I have a "Microsoft Serial BallPoint"; XP will re-install it at re-boot, and create a conflict. If you see that, "Disable" it and forget about it. It is a common problem. Also, check the 'Ports (COM & LPT)' tab for errors under Device Manger. If COMs are all clean, maybe a re-install of WL5.5 is in order. I think WL5.5 uses the "STATION.CFG" file to store com settings, and that might be hosed up. Good luck Rex - K8CYJ -AR863 Subject: [wxqc] Problem with Weatherlink 5.5 and Com Port I'm not sure if brought this on myself by foolin' with the com settings, and I'm not sure how to fix it. Thought maybe someone could offer a suggestion. Running Windows XP, if I reboot the PC, or if there's a power failure with abrupt termination, then re-launch Weatherlink, it dumps out of the upload with the following error in the log "Weatherlink tried to open a comport that is in use by another program. Please wait for the other program to finish, or close the other program." I have to disable the com port, rebott the PC, and enable the com port in order for it to hook up again. Is there something I'm doing wrong, or is this how it works. Tnx, Tom Hybiske, K3GM -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050719/a98fc6f1/attachment.html From t_biskit at yahoo.com Wed Jul 20 07:02:52 2005 From: t_biskit at yahoo.com (Thomas Hybiske) Date: Wed Jul 20 07:02:56 2005 Subject: [wxqc] Problem with Weatherlink 5.5 and Com Port In-Reply-To: <000001c58cdc$bc8df1c0$0100a8c0@DJSSJ661> Message-ID: <20050720110252.47694.qmail@web52712.mail.yahoo.com> Thanks Rex. Going on your sugestion, I browsed around "Device Manager" and located the conflict. (although the system said there was none). I'm running a brand new out of the box Dell, and initially tried to hook it directly to my old PC using a cross-over ethernet cable (didn't work) fo file transfer. The setup wizzard assigned the ethernet port to COM1 which had been assigned to the serial port too. I disabled the driver and rebooted. All is well. Thanks for the help.........Tom Hybiske, K3GM Rex Pirkle wrote: st1\:*{behavior:url(#default#ieooui) } Tom, If your system died in a power failure, run scandisk first to make sure you do not have any disk errors, WL5.5 might be reading a corrupted file. Then check to see if you have created a conflict on your COM port: START>PROGRAMS>ACCESSORIES>SYSTEM TOOLS>SYSTEM INFORMATION Check through the 'Hardware Resource" summaries, 'Conflicts/Sharing', IRQ's etc. to see that the 'Status' checks are all 'OK'. Davis docs for Vantage Pro 2 say,? The console uses a serial or USB port... If you are connecting the console directly to the computer, leave the setting at 19200, the highest rate for the port. Vantage Pro2 supports baud rates of 1200,2400, 4800, 9600, 14400, 19200" If you do not 'auto detect' the Com port in WL5.5 set-up, you will have to match the baud rate of you com port setting. Party-data-stop should be N-8-1. >From the Desktop, RIGHT-click 'My Computer', select 'Properties', then 'Device Manager'. Check under "Mice and other pointing devices' and "Modems", making sure that XP didn't slip in a device driver that doesn't belong there. These are serial devices and XP will sometimes auto-install an incorrect device driver there, creating a conflict. If you see something wrong, either 'Uninstall' or 'Disable' it. My guess is that this is the likely problem. By disable/re-boot/enable sequence, you deny XP the chance to slip its own conflicting device driver in at start-up. It cannot load it because you disabled the port. Check the windows startup log to look for clues. On my machine, XP is convinced that I have a "Microsoft Serial BallPoint"; XP will re-install it at re-boot, and create a conflict. If you see that, "Disable" it and forget about it. It is a common problem. Also, check the 'Ports (COM & LPT)' tab for errors under Device Manger. If COMs are all clean, maybe a re-install of WL5.5 is in order. I think WL5.5 uses the "STATION.CFG" file to store com settings, and that might be hosed up. Good luck Rex - K8CYJ -AR863 Subject: [wxqc] Problem with Weatherlink 5.5 and Com Port I'm not sure if brought this on myself by foolin' with the com settings, and I'm not sure how to fix it. Thought maybe someone could offer a suggestion. Running Windows XP, if I reboot the PC, or if there's a power failure with abrupt termination, then re-launch Weatherlink, it dumps out of the upload with the following error in the log "Weatherlink tried to open a comport that is in use by another program. Please wait for the other program to finish, or close the other program." I have to disable the com port, rebott the PC, and enable the com port in order for it to hook up again. Is there something I'm doing wrong, or is this how it works. Tnx, Tom Hybiske, K3GM _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. --------------------------------- Start your day with Yahoo! - make it your home page -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050720/50644a44/attachment-0001.html From jmcmurry at mwt.net Thu Jul 21 12:07:57 2005 From: jmcmurry at mwt.net (Jim McMurry) Date: Thu Jul 21 12:08:09 2005 Subject: [wxqc] WeatherLink Script Message-ID: George, Please forward me your script when you get a chance. By the way, what software do you use to remotely reboot? - Jim -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050721/4c329e24/attachment.html From jrjones26 at direcway.com Mon Jul 25 16:52:49 2005 From: jrjones26 at direcway.com (Jack Jones) Date: Mon Jul 25 16:53:04 2005 Subject: [wxqc] Dewpoint Data Quality Message-ID: <000d01c5915a$d483f8b0$6401a8c0@intel3200> I am in a quandry over the accuracy of the dew point data of my Davis Vantage Pro. My data is rated as unacceptable based on your computer model. My unit is a wireless unit and the sensor is located at the top of an 8' 4x4 which is buried about 18" so the sensor is about 6.5' above grade. There is a small metal building (6'x6') close by (18") and the roof height is about 5' at that point rising to 5.5' in another 3'. The sensor is in the standard naturally aspirated closure and the ground underneath is bare dirt or closely cut grass. The Davis station shows the humidity here to be at 100% every night for at least 12 hours & the dew point & ambient temperature are the same until about 10:00am. However, that is not inconsistent with my observations. Even during the 43 days from June 1 to July 14 where we had no measurable rainfall, I had low fog nearly every morning until 8 or 10 am. The other times the humidity & dew point have risen sharply since July 14 were during periods of rainfall & they remained elevated for some period of time after the end of the rain. There is another individual reporting weather info to Wunderground that is located about 20 miles south of my station. His dew point & humidity data is usually the same as mine or within 1 degree F. My question is, am I in an area that your model cannot accurately predict or do I and the other guy 20 miles south of me have faulty equipment? I have considered buying a 2nd temperature sensor to check the accuracy but $150 plus cost to do that is slowing me down. Jack Jones CW3934 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050725/618ec2c7/attachment.html From sniadoch at frontiernet.net Mon Jul 25 16:57:21 2005 From: sniadoch at frontiernet.net (Hank Sniadoch) Date: Mon Jul 25 16:59:45 2005 Subject: [wxqc] Dewpoint Data Quality In-Reply-To: <000d01c5915a$d483f8b0$6401a8c0@intel3200> References: <000d01c5915a$d483f8b0$6401a8c0@intel3200> Message-ID: <42E55231.8090000@frontiernet.net> First of all, don't go out and spend any money yet !! Then, wait for a few days and see what the data says (after a few days worth of data) .... then decide .... lastly, don't necessarily believe what someone tells you .... maybe your data is real !! Jack Jones wrote: > I am in a quandry over the accuracy of the dew point data of my Davis > Vantage Pro. My data is rated as unacceptable based on your computer > model. My unit is a wireless unit and the sensor is located at the > top of an 8' 4x4 which is buried about 18" so the sensor is about 6.5' > above grade. There is a small metal building (6'x6') close by (18") > and the roof height is about 5' at that point rising to 5.5' in > another 3'. The sensor is in the standard naturally aspirated closure > and the ground underneath is bare dirt or closely cut grass. > > The Davis station shows the humidity here to be at 100% every night > for at least 12 hours & the dew point & ambient temperature are the > same until about 10:00am. However, that is not inconsistent with my > observations. Even during the 43 days from June 1 to July 14 where we > had no measurable rainfall, I had low fog nearly every morning until 8 > or 10 am. The other times the humidity & dew point have risen sharply > since July 14 were during periods of rainfall & they remained elevated > for some period of time after the end of the rain. There is another > individual reporting weather info to Wunderground that is located > about 20 miles south of my station. His dew point & humidity data is > usually the same as mine or within 1 degree F. > > My question is, am I in an area that your model cannot accurately > predict or do I and the other guy 20 miles south of me have faulty > equipment? I have considered buying a 2nd temperature sensor to check > the accuracy but $150 plus cost to do that is slowing me down. > > Jack Jones > CW3934 > >------------------------------------------------------------------------ > >_______________________________________________ >wxqc mailing list >wxqc@lists.gladstonefamily.net >http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > From philip at gladstonefamily.net Mon Jul 25 22:36:17 2005 From: philip at gladstonefamily.net (Philip Gladstone) Date: Mon Jul 25 22:36:16 2005 Subject: [wxqc] Dewpoint Data Quality In-Reply-To: <000d01c5915a$d483f8b0$6401a8c0@intel3200> References: <000d01c5915a$d483f8b0$6401a8c0@intel3200> Message-ID: <42E5A1A1.6070501@gladstonefamily.net> You can get a sling psychrometer pretty cheaply -- I found a student one online for under $10. This will allow you to measure temperature and humidity. Philip Jack Jones wrote: > I am in a quandry over the accuracy of the dew point data of my Davis > Vantage Pro. My data is rated as unacceptable based on your computer > model. My unit is a wireless unit and the sensor is located at the top > of an 8' 4x4 which is buried about 18" so the sensor is about 6.5' above > grade. There is a small metal building (6'x6') close by (18") and the > roof height is about 5' at that point rising to 5.5' in another 3'. The > sensor is in the standard naturally aspirated closure and the ground > underneath is bare dirt or closely cut grass. > > The Davis station shows the humidity here to be at 100% every night for > at least 12 hours & the dew point & ambient temperature are the same > until about 10:00am. However, that is not inconsistent with my > observations. Even during the 43 days from June 1 to July 14 where we > had no measurable rainfall, I had low fog nearly every morning until 8 > or 10 am. The other times the humidity & dew point have risen sharply > since July 14 were during periods of rainfall & they remained elevated > for some period of time after the end of the rain. There is another > individual reporting weather info to Wunderground that is located about > 20 miles south of my station. His dew point & humidity data is usually > the same as mine or within 1 degree F. > > My question is, am I in an area that your model cannot accurately > predict or do I and the other guy 20 miles south of me have faulty > equipment? I have considered buying a 2nd temperature sensor to check > the accuracy but $150 plus cost to do that is slowing me down. > > Jack Jones > CW3934 > > > ------------------------------------------------------------------------ > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3322 bytes Desc: S/MIME Cryptographic Signature Url : http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050725/c7e6882c/smime.bin From dshelms at comcast.net Mon Jul 25 23:06:46 2005 From: dshelms at comcast.net (Dave Helms) Date: Mon Jul 25 23:09:55 2005 Subject: [wxqc] Dewpoint Data Quality In-Reply-To: <42E55231.8090000@frontiernet.net> References: <000d01c5915a$d483f8b0$6401a8c0@intel3200> <42E55231.8090000@frontiernet.net> Message-ID: <42E5A8C6.4000800@comcast.net> Hi Jack, I see your dew point has been ranging between 75F and 85F for several weeks now under the predominant southeast flow from the Gulf or Mexico. ASOS stations closest to you, Victoria (KVCT) to your south and New Braunfels (KBAZ) to your northwest have been ranging between 68-76F for their dew point measurements: http://weather.gladstonefamily.net/qchart/C3934?date=20050726&addnl=KVCT&addnl=KBAZ&Add+to+charts=Add+to+charts&.cgifields=addnl Seems like your siting is OK, so I would dismiss that as a possible source of the problem. Southeast Texas is one of the most very humid places on Earth, save for the interior Amazon River. That said, dew points above 79F is rather rare even for Texas. I agree with you and the MADIS QCMS statistics that, after about 6 weeks of statistics, your humidity sensor is probably running 5-6F too high for your location: http://weather.gladstonefamily.net/site/C3934 Is there an adjustment screw for your Davis VP humidity sensor (I have used such a screw to adjust downward my Peet Ultimeter RH sensor downward)? Maybe Davis tech support could make an adjustment suggestion or maybe they would accept a free sensor swap? As Philip says, you can get a sling psychrometer for less than $20 on Ebay, but you have to watch the pages for a good buy. Please let us know how things turn out, Dave CW0351 Hank Sniadoch wrote: > First of all, don't go out and spend any money yet !! Then, wait for > a few days and see what the data says (after a few days worth of data) > .... then decide .... lastly, don't necessarily believe what someone > tells you .... maybe your data is real !! > > Jack Jones wrote: > >> I am in a quandry over the accuracy of the dew point data of my Davis >> Vantage Pro. My data is rated as unacceptable based on your computer >> model. My unit is a wireless unit and the sensor is located at the >> top of an 8' 4x4 which is buried about 18" so the sensor is about >> 6.5' above grade. There is a small metal building (6'x6') close by >> (18") and the roof height is about 5' at that point rising to 5.5' in >> another 3'. The sensor is in the standard naturally aspirated >> closure and the ground underneath is bare dirt or closely cut grass. >> >> The Davis station shows the humidity here to be at 100% every night >> for at least 12 hours & the dew point & ambient temperature are the >> same until about 10:00am. However, that is not inconsistent with my >> observations. Even during the 43 days from June 1 to July 14 where >> we had no measurable rainfall, I had low fog nearly every morning >> until 8 or 10 am. The other times the humidity & dew point have risen >> sharply since July 14 were during periods of rainfall & they remained >> elevated for some period of time after the end of the rain. There is >> another individual reporting weather info to Wunderground that is >> located about 20 miles south of my station. His dew point & humidity >> data is usually the same as mine or within 1 degree F. >> >> My question is, am I in an area that your model cannot accurately >> predict or do I and the other guy 20 miles south of me have faulty >> equipment? I have considered buying a 2nd temperature sensor to >> check the accuracy but $150 plus cost to do that is slowing me down. >> >> Jack Jones >> CW3934 >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> wxqc mailing list >> wxqc@lists.gladstonefamily.net >> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >> >> The contents of this message are the responsibility of the author. >> > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > From jrjones26 at direcway.com Tue Jul 26 19:22:02 2005 From: jrjones26 at direcway.com (Jack Jones) Date: Tue Jul 26 19:22:20 2005 Subject: [wxqc] Dewpoint Data Quality References: <000d01c5915a$d483f8b0$6401a8c0@intel3200> <42E5A1A1.6070501@gladstonefamily.net> Message-ID: <001201c59238$dac75e90$6501a8c0@intel3200> Okay folks, I suddenly remembered I had a temperature- relative humidity measuring device already. I just hadn't used it in a few years. It appears to be so sensitive that you cannot obtain a "rock solid" reading with it but it seemed to indicate my humidity values may be about 4 to 5% high and the temperature maybe a half degree low, which would compound the humidity/dewpoint errors. My only explanation for the 85 degree dewpoint numbers are that they occur between 7 and 10 AM, so what must be happening is that after the sun rises and heating begins, it is evaporating the dew that has been condensed overnight. By the time the dew is evaporated, the ambient temp. and dewpoint temp. separate and the dewpoints approach forecast values. Do you have that phenomenon programmed in your model? That explanation would account for some of the variances and if you were here you might understand it as well. It certainly feels as if the humidity is 100% here up to 10:00am or so. Think about that. Jack ----- Original Message ----- From: "Philip Gladstone" To: "Discussion of data quality issues" Sent: Monday, July 25, 2005 9:36 PM Subject: Re: [wxqc] Dewpoint Data Quality > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From pirkle at texoma.net Tue Jul 26 21:46:30 2005 From: pirkle at texoma.net (Rex Pirkle) Date: Tue Jul 26 21:46:39 2005 Subject: [wxqc] RE: Dewpoint Data Quality Message-ID: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> Jack, I am by no means a weather expert, but I will make these comments about your station readings: First, dew point is a calculation based on outside temperature and relative humidity. In the APRS data reporting method, both numbers are rounded to the nearest integer. At high RH the round-off errors alone introduce over 1 deg F error in dew point calculation. Furthermore, the Vantage Pro states the 'Nominal Accuracy' of Outside Humidity at +/- 3%RH, and 4% above 90%RH. The stated VP 'Nominal Accuracy' of Outside temperature is +/- 1 deg F. Add all these errors up, and you have about a 4 degree F dew point drift over time on a properly calibrated Vantage Pro. The QC 'model' seems to like your temperature data, reporting <0.1 F error on average. Obviously, the RH reports are in question. You stated that, "...during the 43 days from June 1 to July 14 where we had no measurable rainfall, I had low fog nearly every morning until 8 or 10 am." Now, my understanding is that a fog condition can only exist when the outside temperature falls to the dew point temperature. Reviewing the model data I didn't see any instance where that occurs; the dew point is always modeled significantly lower that outside temp. Hmm, now how is that possible? Rex Pirkle From dshelms at comcast.net Tue Jul 26 22:33:04 2005 From: dshelms at comcast.net (Dave Helms) Date: Tue Jul 26 22:33:08 2005 Subject: [wxqc] RE: Dewpoint Data Quality In-Reply-To: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> References: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> Message-ID: <42E6F260.4050807@comcast.net> Jack, Fog and ground fog can, and often does, form with RH less than 100%. When determining the cause of horizontal visibility obscuration, you can code fog officially with temperature/dew points separation of up to 7 F degrees, but fog is most often present when temperatures/dew point depressions are less than 4 F degrees. Then again, you can be 100% RH and have no fog. The QC model only "knows" how your station's observations compare how your adjacent south/central Texas station reports. Dave Rex Pirkle wrote: >Jack, >I am by no means a weather expert, but I will make these comments about >your station readings: > >First, dew point is a calculation based on outside temperature and >relative humidity. In the APRS data reporting method, both numbers are >rounded to the nearest integer. At high RH the round-off errors alone >introduce over 1 deg F error in dew point calculation. Furthermore, the >Vantage Pro states the 'Nominal Accuracy' of Outside Humidity at +/- >3%RH, and 4% above 90%RH. The stated VP 'Nominal Accuracy' of Outside >temperature is +/- 1 deg F. Add all these errors up, and you have about >a 4 degree F dew point drift over time on a properly calibrated Vantage >Pro. > >The QC 'model' seems to like your temperature data, reporting <0.1 F >error on average. Obviously, the RH reports are in question. You >stated that, "...during the 43 days from June 1 to July 14 where we had >no measurable rainfall, I had low fog nearly every morning until 8 or 10 >am." Now, my understanding is that a fog condition can only exist when >the outside temperature falls to the dew point temperature. Reviewing >the model data I didn't see any instance where that occurs; the dew >point is always modeled significantly lower that outside temp. Hmm, >now how is that possible? > >Rex Pirkle > > > > >_______________________________________________ >wxqc mailing list >wxqc@lists.gladstonefamily.net >http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > > > > From jrjones26 at direcway.com Tue Jul 26 23:39:52 2005 From: jrjones26 at direcway.com (Jack Jones) Date: Tue Jul 26 23:40:02 2005 Subject: [wxqc] RE: Dewpoint Data Quality References: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> <42E6F260.4050807@comcast.net> Message-ID: <001901c5925c$db71ec10$6501a8c0@intel3200> Dave, Currently (9:50pm) my Vantage pro is showing 79Deg F ambient temp, 96% humidity (but really 100% since I have a 4% off-set), and 77 deg F dew point. A station 25 miles south of me, also using a Vantage Pro, is showing 80 deg F ambient temp, 96% humidity, and 79 deg F dew point, KVCT in Victoria, TX ( 42 miles SE) is reporting, 79 deg F ambient temp, 82 % humidity, and 73 deg F dew point. I don't know what equipment KVCT is using. Now if you believe the QC model is correct, then the Vantage Pro stations are obviously providing elevated dew point & humidity readings. Now the Vantage Pro has no means of adjusting the humidity sensor that I know of other than off-setting the actual reading by a fixed percentage which prevents a 100% reading from ever being reported. As I stated in the previous post, I checked the temp & RH this afternoon with a device that may be "squirellier" than the Davis Vantage Pro & it provided different ambient temps & RHs than the VP at that time. Which one is correct? I just checked the station 25 miles south of me, at 10:10pm, it is reporting 79 deg F, 100% humidity, 79 deg F dew point. If this date were not available, I would conclude I just have a faulty piece of equipment & decide where to go from there. Now do you conclude that the Vantage Pro is not accurate enough to provide data for this group or is there an anonoly here? I can't argue with many of the points you have made, but DPs & humidity are apparently hard to measure accurately with moderately priced equipment. Many humidity measuring devices top out at 94 or 95% humidity & the accuracy up to that point is also questionable. As an old experimenter, I hate to see data disregarded because it doesn't fit the theory,i.e. we keep the data thar proves our argument & throw out any that doesn't. In the past, I have seen experiments that threw out more than 50% of the collected data. The retained data supported the theory nicely, but if all the data were used the theory was totally disproved. That's why I have a problem with models. Jack ----- Original Message ----- From: "Dave Helms" To: "Discussion of data quality issues" Sent: Tuesday, July 26, 2005 9:33 PM Subject: Re: [wxqc] RE: Dewpoint Data Quality > Jack, > > Fog and ground fog can, and often does, form with RH less than 100%. When > determining the cause of horizontal visibility obscuration, you can code > fog officially with temperature/dew points separation of up to 7 F > degrees, but fog is most often present when temperatures/dew point > depressions are less than 4 F degrees. Then again, you can be 100% RH and > have no fog. > > The QC model only "knows" how your station's observations compare how your > adjacent south/central Texas station reports. > > Dave > > Rex Pirkle wrote: > >>Jack, >>I am by no means a weather expert, but I will make these comments about >>your station readings: >> >>First, dew point is a calculation based on outside temperature and >>relative humidity. In the APRS data reporting method, both numbers are >>rounded to the nearest integer. At high RH the round-off errors alone >>introduce over 1 deg F error in dew point calculation. Furthermore, the >>Vantage Pro states the 'Nominal Accuracy' of Outside Humidity at +/- >>3%RH, and 4% above 90%RH. The stated VP 'Nominal Accuracy' of Outside >>temperature is +/- 1 deg F. Add all these errors up, and you have about >>a 4 degree F dew point drift over time on a properly calibrated Vantage >>Pro. >> >>The QC 'model' seems to like your temperature data, reporting <0.1 F >>error on average. Obviously, the RH reports are in question. You >>stated that, "...during the 43 days from June 1 to July 14 where we had >>no measurable rainfall, I had low fog nearly every morning until 8 or 10 >>am." Now, my understanding is that a fog condition can only exist when >>the outside temperature falls to the dew point temperature. Reviewing >>the model data I didn't see any instance where that occurs; the dew >>point is always modeled significantly lower that outside temp. Hmm, >>now how is that possible? >>Rex Pirkle >> >> >> >>_______________________________________________ >>wxqc mailing list >>wxqc@lists.gladstonefamily.net >>http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >> >>The contents of this message are the responsibility of the author. >> >> >> > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From Evan.Bookbinder at noaa.gov Wed Jul 27 01:24:04 2005 From: Evan.Bookbinder at noaa.gov (Evan Bookbinder) Date: Wed Jul 27 01:24:09 2005 Subject: [wxqc] RE: Dewpoint Data Quality In-Reply-To: <001901c5925c$db71ec10$6501a8c0@intel3200> References: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> <42E6F260.4050807@comcast.net> <001901c5925c$db71ec10$6501a8c0@intel3200> Message-ID: <42E71A74.1080606@noaa.gov> Jack, I'll provide my input as a NWS Meteorologist, having watched this thread for a few days. KVCT uses a very high tech piece of equipment called the Automated Surface Observing System located at the airport there. These are the official NWS reporting stations -- and the new DTS dewpoint sensors are typically accurate within less than 1F. An analysis of data along the Texas big bend coastal areas shows that your dewpoint should be 72 or 73F with little variance as the airmass over that region is fairly homogenous. An average of Victoria and San Antonio airports should often provide you a very good starting base for comparisons. You mention fog as a defense for your readings. This holds little "water" (no pun intended) because the coastal and offshore buoys in your area sitting on open water also have dewpoints running 73-74F Visibilities in the morning in deep south texas typically range in the 3-5 mile range each morning, but there is a big difference between a thick dense fog (RH typically 100%) and light shallow/ground fog which can develop with humidities as low as 80% in calm winds. Assuming that your weather station is correctly sited a good 5-6 feet off the ground and is in a location that receives true ambient air, I can make a quite certain statement that your instrument is faulty well outside of normal tolerance. I'm not sure if Davis's instruments are having a systematic problem in high moisture environments, but it's clearly a bad sensor. 3-4% tolerance is actually a pretty high quality instrument that Davis offers -- 6-7F error on your dewpoint exceeds this tolerance by a large margin. With that said, I currently have an ASOS Temp/Dpt system in my backyard running tests against several instruments including an older Davis Weather Monitor II...and they're usually VERY close to one another if not exact. A Vantage Pro purchase was in the works, but will have to wait until my move to Kansas City is complete. I know some on here recommend that people tweak the calibration on their equipment, but I find that this often introduces other variables into the mix. Unless there's a way to prove that an instrument is always Y degrees too warm or cold (a static bias), then adjusting the instrument is equally falsifying the data and masking other problems. My recommendation would be to call Davis, explain that their instrument is exceeding tolerance (point them to the QC and airport observations and even this listserv if they have questions) and ask for a replacement. If the problems continue and we notice a larger scale problem over the deep south, then maybe we need to contact a representative from Davis and do some further testing in a controlled high moisture environment. Thanks, Evan WFO Springfield MO From clayj at nwlink.com Wed Jul 27 02:02:26 2005 From: clayj at nwlink.com (Clay Jackson) Date: Wed Jul 27 02:03:34 2005 Subject: [wxqc] RE: Dewpoint Data Quality In-Reply-To: <42E71A74.1080606@noaa.gov> References: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> <42E6F260.4050807@comcast.net> <001901c5925c$db71ec10$6501a8c0@intel3200> <42E71A74.1080606@noaa.gov> Message-ID: <2FD3DC85-2D1D-478A-9E6A-8CA257A9C185@nwlink.com> Interesting discussion - this may or not be related; but, about 3 weeks ago, I started getting QC "bounces" on my dewpoint data, from a Davis WMII. So, I started investigating, and found that my RH was consistently reading 3-6% high (based on a sling wet/dry bulb thermometer, the model AND 2 other local stations). Since this just started happening after several years of "good" data; I contacted Davis, and they decided I had a bad sensor - they apparently have seen this failure mode before. It's LONG out of warranty, and in fact they have no more "new" sensors; but, they're sending me a refurbished unit; so, hopefully I'll be back in business shortly. Based on my discussions with Davis, I would agree with Evan - it's probably a bad sensor. Clay Jackson On Jul 26, 2005, at 10:24 PM, Evan Bookbinder wrote: > Jack, > > I'll provide my input as a NWS Meteorologist, having watched this > thread for a few days. KVCT uses a very high tech piece of > equipment called the Automated Surface Observing System located at > the airport there. These are the official NWS reporting stations -- > and the new DTS dewpoint sensors are typically accurate within less > than 1F. An analysis of data along the Texas big bend coastal areas > shows that your dewpoint should be 72 or 73F with little variance > as the airmass over that region is fairly homogenous. An average of > Victoria and San Antonio airports should often provide you a very > good starting base for comparisons. > > You mention fog as a defense for your readings. This holds little > "water" (no pun intended) because the coastal and offshore buoys in > your area sitting on open water also have dewpoints running 73-74F > Visibilities in the morning in deep south texas typically range in > the 3-5 mile range each morning, but there is a big difference > between a thick dense fog (RH typically 100%) and light shallow/ > ground fog which can develop with humidities as low as 80% in calm > winds. > > Assuming that your weather station is correctly sited a good 5-6 > feet off the ground and is in a location that receives true ambient > air, I can make a quite certain statement that your instrument is > faulty well outside of normal tolerance. I'm not sure if Davis's > instruments are having a systematic problem in high moisture > environments, but it's clearly a bad sensor. 3-4% tolerance is > actually a pretty high quality instrument that Davis offers -- 6-7F > error on your dewpoint exceeds this tolerance by a large margin. > > With that said, I currently have an ASOS Temp/Dpt system in my > backyard running tests against several instruments including an > older Davis Weather Monitor II...and they're usually VERY close to > one another if not exact. A Vantage Pro purchase was in the works, > but will have to wait until my move to Kansas City is complete. > > I know some on here recommend that people tweak the calibration on > their equipment, but I find that this often introduces other > variables into the mix. Unless there's a way to prove that an > instrument is always Y degrees too warm or cold (a static bias), > then adjusting the instrument is equally falsifying the data and > masking other problems. > > My recommendation would be to call Davis, explain that their > instrument is exceeding tolerance (point them to the QC and airport > observations and even this listserv if they have questions) and > ask for a replacement. If the problems continue and we notice a > larger scale problem over the deep south, then maybe we need to > contact a representative from Davis and do some further testing in > a controlled high moisture environment. > > Thanks, > Evan > WFO Springfield MO > > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > From dshelms at comcast.net Wed Jul 27 08:25:51 2005 From: dshelms at comcast.net (Dave Helms) Date: Wed Jul 27 08:25:48 2005 Subject: [wxqc] RE: Dewpoint Data Quality In-Reply-To: <2FD3DC85-2D1D-478A-9E6A-8CA257A9C185@nwlink.com> References: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> <42E6F260.4050807@comcast.net> <001901c5925c$db71ec10$6501a8c0@intel3200> <42E71A74.1080606@noaa.gov> <2FD3DC85-2D1D-478A-9E6A-8CA257A9C185@nwlink.com> Message-ID: <42E77D4E.2050704@comcast.net> Hi Clay, That is the nature of the technology, e.g. humidity sensors (typically thin film capacitors (TFC)) "drift" (or become "seasoned") over time, which means they become less responsive over time. Where your data once was in spec routinely, it may be the case that over 2-3 years the measurements will no longer provide quality data in the lower end of the required performance range (e.g. RH measurements less than 90%). This is why checking performance for a RH sensor performance during an extended period of high humidities will not typically reveal low end range sensitivity problems, making the RH sensor's performance look better than it really is. Said another way, almost any RH sensor will measure 100% conditions well, it is the better performing sensors that will yield steady performance as the atmosphere dries out. The Peet Bros circuit board has a little "sponge" (TFC) that sits in the circuit board which can be removed and replaced without replacing the entire temp/RH sensor. FYI... Philip and I have yet to flesh out the RH/Dew Point "failure modes" for the automated QC messages. The text that appears today for RH/DP is pretty generic when the mean error and standard deviation thresholds are exceeded. We hope to work on this area in the future. FYI2... Like Even, I don't advise using software offsets to "correct" RH problems. As he says, this only masks the problem. The fix should be done directly on the RH sensor's hardware; e.g., by adjusting the potentiometer on the circuit board (as can be done with the Peet), or through replacement of the TFC on the circuit board, or through replacement of the entire sensor circuit board. Dave CW0351 Clay Jackson wrote: > Interesting discussion - this may or not be related; but, about 3 > weeks ago, I started getting QC "bounces" on my dewpoint data, from a > Davis WMII. So, I started investigating, and found that my RH was > consistently reading 3-6% high (based on a sling wet/dry bulb > thermometer, the model AND 2 other local stations). Since this just > started happening after several years of "good" data; I contacted > Davis, and they decided I had a bad sensor - they apparently have > seen this failure mode before. It's LONG out of warranty, and in > fact they have no more "new" sensors; but, they're sending me a > refurbished unit; so, hopefully I'll be back in business shortly. > > Based on my discussions with Davis, I would agree with Evan - it's > probably a bad sensor. > > Clay Jackson > > On Jul 26, 2005, at 10:24 PM, Evan Bookbinder wrote: > >> Jack, >> >> I'll provide my input as a NWS Meteorologist, having watched this >> thread for a few days. KVCT uses a very high tech piece of equipment >> called the Automated Surface Observing System located at the airport >> there. These are the official NWS reporting stations -- and the new >> DTS dewpoint sensors are typically accurate within less than 1F. An >> analysis of data along the Texas big bend coastal areas shows that >> your dewpoint should be 72 or 73F with little variance as the >> airmass over that region is fairly homogenous. An average of >> Victoria and San Antonio airports should often provide you a very >> good starting base for comparisons. >> >> You mention fog as a defense for your readings. This holds little >> "water" (no pun intended) because the coastal and offshore buoys in >> your area sitting on open water also have dewpoints running 73-74F >> Visibilities in the morning in deep south texas typically range in >> the 3-5 mile range each morning, but there is a big difference >> between a thick dense fog (RH typically 100%) and light shallow/ >> ground fog which can develop with humidities as low as 80% in calm >> winds. >> >> Assuming that your weather station is correctly sited a good 5-6 >> feet off the ground and is in a location that receives true ambient >> air, I can make a quite certain statement that your instrument is >> faulty well outside of normal tolerance. I'm not sure if Davis's >> instruments are having a systematic problem in high moisture >> environments, but it's clearly a bad sensor. 3-4% tolerance is >> actually a pretty high quality instrument that Davis offers -- 6-7F >> error on your dewpoint exceeds this tolerance by a large margin. >> >> With that said, I currently have an ASOS Temp/Dpt system in my >> backyard running tests against several instruments including an >> older Davis Weather Monitor II...and they're usually VERY close to >> one another if not exact. A Vantage Pro purchase was in the works, >> but will have to wait until my move to Kansas City is complete. >> >> I know some on here recommend that people tweak the calibration on >> their equipment, but I find that this often introduces other >> variables into the mix. Unless there's a way to prove that an >> instrument is always Y degrees too warm or cold (a static bias), >> then adjusting the instrument is equally falsifying the data and >> masking other problems. >> >> My recommendation would be to call Davis, explain that their >> instrument is exceeding tolerance (point them to the QC and airport >> observations and even this listserv if they have questions) and ask >> for a replacement. If the problems continue and we notice a larger >> scale problem over the deep south, then maybe we need to contact a >> representative from Davis and do some further testing in a >> controlled high moisture environment. >> >> Thanks, >> Evan >> WFO Springfield MO >> >> >> _______________________________________________ >> wxqc mailing list >> wxqc@lists.gladstonefamily.net >> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >> >> The contents of this message are the responsibility of the author. >> >> > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > From jrjones26 at direcway.com Wed Jul 27 13:37:34 2005 From: jrjones26 at direcway.com (Jack Jones) Date: Wed Jul 27 13:37:47 2005 Subject: [wxqc] RE: Dewpoint Data Quality References: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> <42E6F260.4050807@comcast.net> <001901c5925c$db71ec10$6501a8c0@intel3200> <42E71A74.1080606@noaa.gov> <2FD3DC85-2D1D-478A-9E6A-8CA257A9C185@nwlink.com> <42E77D4E.2050704@comcast.net> Message-ID: <001101c592d1$e1e74f20$6401a8c0@intel3200> Well folks, I thank you all for the comments on my problem. I finally got a response from Davis Instruments & they have concluded the humidity sensor is faulty. They will repair the unit for $79 but I have to send them the unit. I'll do that so I'll be out of the network for 3 weeks or so. Jack ----- Original Message ----- From: "Dave Helms" To: "Discussion of data quality issues" Sent: Wednesday, July 27, 2005 7:25 AM Subject: Re: [wxqc] RE: Dewpoint Data Quality > Hi Clay, > > That is the nature of the technology, e.g. humidity sensors (typically > thin film capacitors (TFC)) "drift" (or become "seasoned") over time, > which means they become less responsive over time. Where your data once > was in spec routinely, it may be the case that over 2-3 years the > measurements will no longer provide quality data in the lower end of the > required performance range (e.g. RH measurements less than 90%). This is > why checking performance for a RH sensor performance during an extended > period of high humidities will not typically reveal low end range > sensitivity problems, making the RH sensor's performance look better than > it really is. Said another way, almost any RH sensor will measure 100% > conditions well, it is the better performing sensors that will yield > steady performance as the atmosphere dries out. > > The Peet Bros circuit board has a little "sponge" (TFC) that sits in the > circuit board which can be removed and replaced without replacing the > entire temp/RH sensor. > > FYI... Philip and I have yet to flesh out the RH/Dew Point "failure modes" > for the automated QC messages. The text that appears today for RH/DP is > pretty generic when the mean error and standard deviation thresholds are > exceeded. We hope to work on this area in the future. > > FYI2... Like Even, I don't advise using software offsets to "correct" RH > problems. As he says, this only masks the problem. The fix should be > done directly on the RH sensor's hardware; e.g., by adjusting the > potentiometer on the circuit board (as can be done with the Peet), or > through replacement of the TFC on the circuit board, or through > replacement of the entire sensor circuit board. > > Dave > CW0351 > > > Clay Jackson wrote: > >> Interesting discussion - this may or not be related; but, about 3 weeks >> ago, I started getting QC "bounces" on my dewpoint data, from a Davis >> WMII. So, I started investigating, and found that my RH was consistently >> reading 3-6% high (based on a sling wet/dry bulb thermometer, the model >> AND 2 other local stations). Since this just started happening after >> several years of "good" data; I contacted Davis, and they decided I had >> a bad sensor - they apparently have seen this failure mode before. It's >> LONG out of warranty, and in fact they have no more "new" sensors; but, >> they're sending me a refurbished unit; so, hopefully I'll be back in >> business shortly. >> >> Based on my discussions with Davis, I would agree with Evan - it's >> probably a bad sensor. >> >> Clay Jackson >> >> On Jul 26, 2005, at 10:24 PM, Evan Bookbinder wrote: >> >>> Jack, >>> >>> I'll provide my input as a NWS Meteorologist, having watched this >>> thread for a few days. KVCT uses a very high tech piece of equipment >>> called the Automated Surface Observing System located at the airport >>> there. These are the official NWS reporting stations -- and the new DTS >>> dewpoint sensors are typically accurate within less than 1F. An >>> analysis of data along the Texas big bend coastal areas shows that your >>> dewpoint should be 72 or 73F with little variance as the airmass over >>> that region is fairly homogenous. An average of Victoria and San >>> Antonio airports should often provide you a very good starting base for >>> comparisons. >>> >>> You mention fog as a defense for your readings. This holds little >>> "water" (no pun intended) because the coastal and offshore buoys in >>> your area sitting on open water also have dewpoints running 73-74F >>> Visibilities in the morning in deep south texas typically range in the >>> 3-5 mile range each morning, but there is a big difference between a >>> thick dense fog (RH typically 100%) and light shallow/ ground fog which >>> can develop with humidities as low as 80% in calm winds. >>> >>> Assuming that your weather station is correctly sited a good 5-6 feet >>> off the ground and is in a location that receives true ambient air, I >>> can make a quite certain statement that your instrument is faulty well >>> outside of normal tolerance. I'm not sure if Davis's instruments are >>> having a systematic problem in high moisture environments, but it's >>> clearly a bad sensor. 3-4% tolerance is actually a pretty high quality >>> instrument that Davis offers -- 6-7F error on your dewpoint exceeds >>> this tolerance by a large margin. >>> >>> With that said, I currently have an ASOS Temp/Dpt system in my backyard >>> running tests against several instruments including an older Davis >>> Weather Monitor II...and they're usually VERY close to one another if >>> not exact. A Vantage Pro purchase was in the works, but will have to >>> wait until my move to Kansas City is complete. >>> >>> I know some on here recommend that people tweak the calibration on >>> their equipment, but I find that this often introduces other variables >>> into the mix. Unless there's a way to prove that an instrument is >>> always Y degrees too warm or cold (a static bias), then adjusting the >>> instrument is equally falsifying the data and masking other problems. >>> >>> My recommendation would be to call Davis, explain that their instrument >>> is exceeding tolerance (point them to the QC and airport observations >>> and even this listserv if they have questions) and ask for a >>> replacement. If the problems continue and we notice a larger scale >>> problem over the deep south, then maybe we need to contact a >>> representative from Davis and do some further testing in a controlled >>> high moisture environment. >>> >>> Thanks, >>> Evan >>> WFO Springfield MO >>> >>> >>> _______________________________________________ >>> wxqc mailing list >>> wxqc@lists.gladstonefamily.net >>> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >>> >>> The contents of this message are the responsibility of the author. >>> >>> >> >> _______________________________________________ >> wxqc mailing list >> wxqc@lists.gladstonefamily.net >> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >> >> The contents of this message are the responsibility of the author. >> >> > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From gary.oldham at adelphia.net Wed Jul 27 13:58:52 2005 From: gary.oldham at adelphia.net (Gary Oldham) Date: Wed Jul 27 13:59:11 2005 Subject: [wxqc] RE: Dewpoint Data Quality Message-ID: <30241482.1122487132953.JavaMail.root@web4.mail.adelphia.net> Jack - I haven't closely followed this thread, but rather caught bits and pieces. I can't recall if you're using a Weather Monitor/Wizard or a newer Vantage Pro. At least for the Vantage Pro line, Davis is usually quite willing to send out a replacement part - new or refurbished - along with an invoice, then when you return the defective part, they tear up the invoice. Particularly for the newer Vantage Pro, they're willing to do this with no cost to the user, except the cost of shipping the defective part back to them. Now, it's their call, of course, if the unit is out of warranty, but they've been pretty consistent about this approach. I don't know that there's any difference between the Vantage Pro 1 and Vantage Pro 2 humidity sensor; I don't think there is. If there is a difference, though, I suppose they could be out of VP1 humidity sensors leaving them no choice but a repair. You might want to call Brett Lane, their tech support supervisor, and speak with him. It sounds to me like they're not being as accomodating as usual. You also might mention that many people with the CWOP program have been following your plight, that might also help motivate them... Good luck, Gary gary.oldham(at)adelphia.net ---- Jack Jones wrote: ============= Well folks, I thank you all for the comments on my problem. I finally got a response from Davis Instruments & they have concluded the humidity sensor is faulty. They will repair the unit for $79 but I have to send them the unit. I'll do that so I'll be out of the network for 3 weeks or so. Jack ----- Original Message ----- From: "Dave Helms" To: "Discussion of data quality issues" Sent: Wednesday, July 27, 2005 7:25 AM Subject: Re: [wxqc] RE: Dewpoint Data Quality > Hi Clay, > > That is the nature of the technology, e.g. humidity sensors (typically > thin film capacitors (TFC)) "drift" (or become "seasoned") over time, > which means they become less responsive over time. Where your data once > was in spec routinely, it may be the case that over 2-3 years the > measurements will no longer provide quality data in the lower end of the > required performance range (e.g. RH measurements less than 90%). This is > why checking performance for a RH sensor performance during an extended > period of high humidities will not typically reveal low end range > sensitivity problems, making the RH sensor's performance look better than > it really is. Said another way, almost any RH sensor will measure 100% > conditions well, it is the better performing sensors that will yield > steady performance as the atmosphere dries out. > > The Peet Bros circuit board has a little "sponge" (TFC) that sits in the > circuit board which can be removed and replaced without replacing the > entire temp/RH sensor. > > FYI... Philip and I have yet to flesh out the RH/Dew Point "failure modes" > for the automated QC messages. The text that appears today for RH/DP is > pretty generic when the mean error and standard deviation thresholds are > exceeded. We hope to work on this area in the future. > > FYI2... Like Even, I don't advise using software offsets to "correct" RH > problems. As he says, this only masks the problem. The fix should be > done directly on the RH sensor's hardware; e.g., by adjusting the > potentiometer on the circuit board (as can be done with the Peet), or > through replacement of the TFC on the circuit board, or through > replacement of the entire sensor circuit board. > > Dave > CW0351 > > > Clay Jackson wrote: > >> Interesting discussion - this may or not be related; but, about 3 weeks >> ago, I started getting QC "bounces" on my dewpoint data, from a Davis >> WMII. So, I started investigating, and found that my RH was consistently >> reading 3-6% high (based on a sling wet/dry bulb thermometer, the model >> AND 2 other local stations). Since this just started happening after >> several years of "good" data; I contacted Davis, and they decided I had >> a bad sensor - they apparently have seen this failure mode before. It's >> LONG out of warranty, and in fact they have no more "new" sensors; but, >> they're sending me a refurbished unit; so, hopefully I'll be back in >> business shortly. >> >> Based on my discussions with Davis, I would agree with Evan - it's >> probably a bad sensor. >> >> Clay Jackson >> >> On Jul 26, 2005, at 10:24 PM, Evan Bookbinder wrote: >> >>> Jack, >>> >>> I'll provide my input as a NWS Meteorologist, having watched this >>> thread for a few days. KVCT uses a very high tech piece of equipment >>> called the Automated Surface Observing System located at the airport >>> there. These are the official NWS reporting stations -- and the new DTS >>> dewpoint sensors are typically accurate within less than 1F. An >>> analysis of data along the Texas big bend coastal areas shows that your >>> dewpoint should be 72 or 73F with little variance as the airmass over >>> that region is fairly homogenous. An average of Victoria and San >>> Antonio airports should often provide you a very good starting base for >>> comparisons. >>> >>> You mention fog as a defense for your readings. This holds little >>> "water" (no pun intended) because the coastal and offshore buoys in >>> your area sitting on open water also have dewpoints running 73-74F >>> Visibilities in the morning in deep south texas typically range in the >>> 3-5 mile range each morning, but there is a big difference between a >>> thick dense fog (RH typically 100%) and light shallow/ ground fog which >>> can develop with humidities as low as 80% in calm winds. >>> >>> Assuming that your weather station is correctly sited a good 5-6 feet >>> off the ground and is in a location that receives true ambient air, I >>> can make a quite certain statement that your instrument is faulty well >>> outside of normal tolerance. I'm not sure if Davis's instruments are >>> having a systematic problem in high moisture environments, but it's >>> clearly a bad sensor. 3-4% tolerance is actually a pretty high quality >>> instrument that Davis offers -- 6-7F error on your dewpoint exceeds >>> this tolerance by a large margin. >>> >>> With that said, I currently have an ASOS Temp/Dpt system in my backyard >>> running tests against several instruments including an older Davis >>> Weather Monitor II...and they're usually VERY close to one another if >>> not exact. A Vantage Pro purchase was in the works, but will have to >>> wait until my move to Kansas City is complete. >>> >>> I know some on here recommend that people tweak the calibration on >>> their equipment, but I find that this often introduces other variables >>> into the mix. Unless there's a way to prove that an instrument is >>> always Y degrees too warm or cold (a static bias), then adjusting the >>> instrument is equally falsifying the data and masking other problems. >>> >>> My recommendation would be to call Davis, explain that their instrument >>> is exceeding tolerance (point them to the QC and airport observations >>> and even this listserv if they have questions) and ask for a >>> replacement. If the problems continue and we notice a larger scale >>> problem over the deep south, then maybe we need to contact a >>> representative from Davis and do some further testing in a controlled >>> high moisture environment. >>> >>> Thanks, >>> Evan >>> WFO Springfield MO >>> >>> >>> _______________________________________________ >>> wxqc mailing list >>> wxqc@lists.gladstonefamily.net >>> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >>> >>> The contents of this message are the responsibility of the author. >>> >>> >> >> _______________________________________________ >> wxqc mailing list >> wxqc@lists.gladstonefamily.net >> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >> >> The contents of this message are the responsibility of the author. >> >> > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list wxqc@lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From clayj at nwlink.com Wed Jul 27 14:26:46 2005 From: clayj at nwlink.com (clayj@nwlink.com) Date: Wed Jul 27 14:26:52 2005 Subject: [wxqc] RE: Dewpoint Data Quality In-Reply-To: <001101c592d1$e1e74f20$6401a8c0@intel3200> References: <000201c5924d$040c4fe0$0100a8c0@DJSSJ661> <42E6F260.4050807@comcast.net> <001901c5925c$db71ec10$6501a8c0@intel3200> <42E71A74.1080606@noaa.gov> <2FD3DC85-2D1D-478A-9E6A-8CA257A9C185@nwlink.com> <42E77D4E.2050704@comcast.net> <001101c592d1$e1e74f20$6401a8c0@intel3200> Message-ID: <10606.167.88.200.30.1122488806.squirrel@webmail.pacifier.com> Jack - I had the same issue when I went the email route. When I CALLED their Tech Support number, the guy I spoke with offered the "advance replacement" option, and the total cost was actually less than the Customer Service guy had quoted me on the email. Give that a shot. Clay Jackson > Well folks, I thank you all for the comments on my problem. I finally got > a > response from Davis Instruments & they have concluded the humidity sensor > is > faulty. They will repair the unit for $79 but I have to send them the > unit. > I'll do that so I'll be out of the network for 3 weeks or so. > > Jack > ----- Original Message ----- > From: "Dave Helms" > To: "Discussion of data quality issues" > Sent: Wednesday, July 27, 2005 7:25 AM > Subject: Re: [wxqc] RE: Dewpoint Data Quality > > >> Hi Clay, >> >> That is the nature of the technology, e.g. humidity sensors (typically >> thin film capacitors (TFC)) "drift" (or become "seasoned") over time, >> which means they become less responsive over time. Where your data once >> was in spec routinely, it may be the case that over 2-3 years the >> measurements will no longer provide quality data in the lower end of the >> required performance range (e.g. RH measurements less than 90%). This >> is >> why checking performance for a RH sensor performance during an extended >> period of high humidities will not typically reveal low end range >> sensitivity problems, making the RH sensor's performance look better >> than >> it really is. Said another way, almost any RH sensor will measure 100% >> conditions well, it is the better performing sensors that will yield >> steady performance as the atmosphere dries out. >> >> The Peet Bros circuit board has a little "sponge" (TFC) that sits in the >> circuit board which can be removed and replaced without replacing the >> entire temp/RH sensor. >> >> FYI... Philip and I have yet to flesh out the RH/Dew Point "failure >> modes" >> for the automated QC messages. The text that appears today for RH/DP is >> pretty generic when the mean error and standard deviation thresholds are >> exceeded. We hope to work on this area in the future. >> >> FYI2... Like Even, I don't advise using software offsets to "correct" RH >> problems. As he says, this only masks the problem. The fix should be >> done directly on the RH sensor's hardware; e.g., by adjusting the >> potentiometer on the circuit board (as can be done with the Peet), or >> through replacement of the TFC on the circuit board, or through >> replacement of the entire sensor circuit board. >> >> Dave >> CW0351 >> >> >> Clay Jackson wrote: >> >>> Interesting discussion - this may or not be related; but, about 3 >>> weeks >>> ago, I started getting QC "bounces" on my dewpoint data, from a Davis >>> WMII. So, I started investigating, and found that my RH was >>> consistently >>> reading 3-6% high (based on a sling wet/dry bulb thermometer, the >>> model >>> AND 2 other local stations). Since this just started happening after >>> several years of "good" data; I contacted Davis, and they decided I >>> had >>> a bad sensor - they apparently have seen this failure mode before. >>> It's >>> LONG out of warranty, and in fact they have no more "new" sensors; >>> but, >>> they're sending me a refurbished unit; so, hopefully I'll be back in >>> business shortly. >>> >>> Based on my discussions with Davis, I would agree with Evan - it's >>> probably a bad sensor. >>> >>> Clay Jackson >>> >>> On Jul 26, 2005, at 10:24 PM, Evan Bookbinder wrote: >>> >>>> Jack, >>>> >>>> I'll provide my input as a NWS Meteorologist, having watched this >>>> thread for a few days. KVCT uses a very high tech piece of equipment >>>> called the Automated Surface Observing System located at the airport >>>> there. These are the official NWS reporting stations -- and the new >>>> DTS >>>> dewpoint sensors are typically accurate within less than 1F. An >>>> analysis of data along the Texas big bend coastal areas shows that >>>> your >>>> dewpoint should be 72 or 73F with little variance as the airmass over >>>> that region is fairly homogenous. An average of Victoria and San >>>> Antonio airports should often provide you a very good starting base >>>> for >>>> comparisons. >>>> >>>> You mention fog as a defense for your readings. This holds little >>>> "water" (no pun intended) because the coastal and offshore buoys in >>>> your area sitting on open water also have dewpoints running 73-74F >>>> Visibilities in the morning in deep south texas typically range in >>>> the >>>> 3-5 mile range each morning, but there is a big difference between a >>>> thick dense fog (RH typically 100%) and light shallow/ ground fog >>>> which >>>> can develop with humidities as low as 80% in calm winds. >>>> >>>> Assuming that your weather station is correctly sited a good 5-6 feet >>>> off the ground and is in a location that receives true ambient air, I >>>> can make a quite certain statement that your instrument is faulty >>>> well >>>> outside of normal tolerance. I'm not sure if Davis's instruments are >>>> having a systematic problem in high moisture environments, but it's >>>> clearly a bad sensor. 3-4% tolerance is actually a pretty high >>>> quality >>>> instrument that Davis offers -- 6-7F error on your dewpoint exceeds >>>> this tolerance by a large margin. >>>> >>>> With that said, I currently have an ASOS Temp/Dpt system in my >>>> backyard >>>> running tests against several instruments including an older Davis >>>> Weather Monitor II...and they're usually VERY close to one another if >>>> not exact. A Vantage Pro purchase was in the works, but will have to >>>> wait until my move to Kansas City is complete. >>>> >>>> I know some on here recommend that people tweak the calibration on >>>> their equipment, but I find that this often introduces other >>>> variables >>>> into the mix. Unless there's a way to prove that an instrument is >>>> always Y degrees too warm or cold (a static bias), then adjusting the >>>> instrument is equally falsifying the data and masking other problems. >>>> >>>> My recommendation would be to call Davis, explain that their >>>> instrument >>>> is exceeding tolerance (point them to the QC and airport observations >>>> and even this listserv if they have questions) and ask for a >>>> replacement. If the problems continue and we notice a larger scale >>>> problem over the deep south, then maybe we need to contact a >>>> representative from Davis and do some further testing in a controlled >>>> high moisture environment. >>>> >>>> Thanks, >>>> Evan >>>> WFO Springfield MO >>>> >>>> >>>> _______________________________________________ >>>> wxqc mailing list >>>> wxqc@lists.gladstonefamily.net >>>> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >>>> >>>> The contents of this message are the responsibility of the author. >>>> >>>> >>> >>> _______________________________________________ >>> wxqc mailing list >>> wxqc@lists.gladstonefamily.net >>> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >>> >>> The contents of this message are the responsibility of the author. >>> >>> >> >> _______________________________________________ >> wxqc mailing list >> wxqc@lists.gladstonefamily.net >> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >> >> The contents of this message are the responsibility of the author. > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > From pirkle at texoma.net Wed Jul 27 19:28:17 2005 From: pirkle at texoma.net (Rex Pirkle) Date: Wed Jul 27 19:27:49 2005 Subject: [wxqc] RE: Dewpoint Data Quality Message-ID: <000001c59302$defb3570$0100a8c0@DJSSJ661> One thought about a simple way to confirm a defective RH or Temp sensor on a Davis Vantage Pro, or Pro2: The VP desktop console has separate built-in humidity and temp sensors that measure INDOOR RH/temp. Just carry the desktop unit outside in 'battery mode', place it near the outdoor sensors and log readings for a couple of hours. Then, download the station log "download.txt" and compare the "indoor" readings to the "outdoor" readings. This will not confirm that either is right, but if the readings are significantly different, something is certainly wrong. Rex Pirkle From jrjones26 at direcway.com Wed Jul 27 20:10:15 2005 From: jrjones26 at direcway.com (Jack Jones) Date: Wed Jul 27 20:10:25 2005 Subject: [wxqc] RE: Dewpoint Data Quality References: <000001c59302$defb3570$0100a8c0@DJSSJ661> Message-ID: <000601c59308$bd830930$6401a8c0@intel3200> Rex, That was a good thought. I wish I had done that a week or two ago. However, its too late now. The outdoor unit has been sent to Davis for repair. Jack ----- Original Message ----- From: "Rex Pirkle" To: Sent: Wednesday, July 27, 2005 6:28 PM Subject: [wxqc] RE: Dewpoint Data Quality > > One thought about a simple way to confirm a defective RH or Temp sensor > on a Davis Vantage Pro, or Pro2: > > The VP desktop console has separate built-in humidity and temp sensors > that measure INDOOR RH/temp. Just carry the desktop unit outside in > 'battery mode', place it near the outdoor sensors and log readings for a > couple of hours. Then, download the station log "download.txt" and > compare the "indoor" readings to the "outdoor" readings. This will not > confirm that either is right, but if the readings are significantly > different, something is certainly wrong. > > Rex Pirkle > > > > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From gary.oldham at adelphia.net Wed Jul 27 21:47:29 2005 From: gary.oldham at adelphia.net (Gary Oldham) Date: Wed Jul 27 21:47:40 2005 Subject: [wxqc] RE: Dewpoint Data Quality In-Reply-To: <000601c59308$bd830930$6401a8c0@intel3200> References: <000001c59302$defb3570$0100a8c0@DJSSJ661> <000601c59308$bd830930$6401a8c0@intel3200> Message-ID: <42E83931.60602@adelphia.net> I'd use some caution with that approach. Davis indicates that the console thermometer and hygrometer are calibrated differently for their expected environment; no shielding for the console instruments, and solar warming of the console will give much, much higher readings. I've had mine outside and had the console thermometer reading over 110 when the ambient air temp was below 90. Gary Jack Jones wrote: > Rex, > > That was a good thought. I wish I had done that a week or two ago. > However, its too late now. The outdoor unit has been sent to Davis > for repair. > > Jack > ----- Original Message ----- From: "Rex Pirkle" > To: > Sent: Wednesday, July 27, 2005 6:28 PM > Subject: [wxqc] RE: Dewpoint Data Quality > > >> >> One thought about a simple way to confirm a defective RH or Temp sensor >> on a Davis Vantage Pro, or Pro2: >> >> The VP desktop console has separate built-in humidity and temp sensors >> that measure INDOOR RH/temp. Just carry the desktop unit outside in >> 'battery mode', place it near the outdoor sensors and log readings for a >> couple of hours. Then, download the station log "download.txt" and >> compare the "indoor" readings to the "outdoor" readings. This will not >> confirm that either is right, but if the readings are significantly >> different, something is certainly wrong. >> >> Rex Pirkle >> >> >> >> >> _______________________________________________ >> wxqc mailing list >> wxqc@lists.gladstonefamily.net >> http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc >> >> The contents of this message are the responsibility of the author. > > > _______________________________________________ > wxqc mailing list > wxqc@lists.gladstonefamily.net > http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From pirkle at texoma.net Thu Jul 28 00:36:25 2005 From: pirkle at texoma.net (Rex Pirkle) Date: Thu Jul 28 00:36:40 2005 Subject: [wxqc] RE: Dewpoint Data Quality Message-ID: <000301c5932d$ec752a00$0100a8c0@DJSSJ661> Granted the VP console Temp/RH indoor sensors are not as robust as the outdoor sensors, but the Davis specs indicate that respectable measurements are possible with the console outdoors: VP2 Console Specs, (Operating/Display Temp range, +32F to +140F) Inside Humidity - Resolution: 1% - Range: 10% to 90% - Nominal Accuracy: 5% RH Inside Temperature - Resolution: 0.1F - Range: +32F to 140F - Nominal Accuracy: +/-1.0F So, I suppose the 'cautions' would be: 1) Do not freeze the console 2) Don't let it rain, snow, or hail on the console 3) Do an indoor/outdoor reading comparison between dusk & dawn to avoid solar warming. 4) Ignore any comparison data below 10% RH or above 90% RH.(out of console range) 5) Turn the console lamps off during check (avoid console heating) By the way, I am learning a LOT reading the WXQC posts and all the CWOP info; great stuff. 'Two Thumbs Up' to all the NOAA gurus -- you do a great job. Rex - K8CYJ-5 /AR863 **************************************************************** I'd use some caution with that approach. Davis indicates that the console thermometer and hygrometer are calibrated differently for their expected environment; no shielding for the console instruments, and solar warming of the console will give much, much higher readings. I've had mine outside and had the console thermometer reading over 110 when the ambient air temp was below 90. Gary From gary.oldham at adelphia.net Thu Jul 28 06:40:58 2005 From: gary.oldham at adelphia.net (Gary Oldham) Date: Thu Jul 28 06:41:12 2005 Subject: [wxqc] RE: Dewpoint Data Quality In-Reply-To: <000301c5932d$ec752a00$0100a8c0@DJSSJ661> References: <000301c5932d$ec752a00$0100a8c0@DJSSJ661> Message-ID: <42E8B63A.8090004@adelphia.net> Nothing there negates my earlier comments - the indoor sensors are calibrated differently. Doesn't mean they are less accurate, actually moreso - they are calibrated for their intended application and environment. I tend to believe Davis' statements about the applications for their own instruments. Along with the clever and amusing comment about not freezing or allowing rain, snow or hail on the console, it does not provide for any sort of ventilation to speak of for the sensors. Solar radiation on the console will cause excessive warming of the sensors and artificially inflated readings. Even in shade, the console temp readings will be excessive outdoors; I'd be skeptical of nighttime readings, too. Comparing readings between the indoor and outdoor sensors will typically not give simliar readings. Gary (One of the tech editors of the CWOP Instrument Siting Guide) One can sometimes actually learn something from rank amateur non-NOAA types, too. Rex Pirkle wrote: >Granted the VP console Temp/RH indoor sensors are not as robust as the >outdoor sensors, but the Davis specs indicate that respectable >measurements are possible with the console outdoors: > >VP2 Console Specs, (Operating/Display Temp range, +32F to +140F) >Inside Humidity >- Resolution: 1% >- Range: 10% to 90% >- Nominal Accuracy: 5% RH > >Inside Temperature >- Resolution: 0.1F >- Range: +32F to 140F >- Nominal Accuracy: +/-1.0F > >So, I suppose the 'cautions' would be: >1) Do not freeze the console >2) Don't let it rain, snow, or hail on the console >3) Do an indoor/outdoor reading comparison between dusk & dawn to avoid >solar warming. >4) Ignore any comparison data below 10% RH or above 90% RH.(out of >console range) >5) Turn the console lamps off during check (avoid console heating) > >By the way, I am learning a LOT reading the WXQC posts and all the CWOP >info; great stuff. 'Two Thumbs Up' to all the NOAA gurus -- you do a >great job. > >Rex - K8CYJ-5 /AR863 > >**************************************************************** >I'd use some caution with that approach. Davis indicates that the >console thermometer and hygrometer are calibrated differently for their >expected environment; no shielding for the console instruments, and >solar warming of the console will give much, much higher readings. I've > >had mine outside and had the console thermometer reading over 110 when >the ambient air temp was below 90. > >Gary > > >_______________________________________________ >wxqc mailing list >wxqc@lists.gladstonefamily.net >http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > > > From dshelms at comcast.net Thu Jul 28 07:15:08 2005 From: dshelms at comcast.net (Dave Helms) Date: Thu Jul 28 07:15:12 2005 Subject: [wxqc] RE: Dewpoint Data Quality (Peet Bros) In-Reply-To: <000301c5932d$ec752a00$0100a8c0@DJSSJ661> References: <000301c5932d$ec752a00$0100a8c0@DJSSJ661> Message-ID: <42E8BE3C.2070306@comcast.net> Hi All: For the Peet Bros folks, Tom (K5BV) in Aransas Pass, Texas, put this document together for making calibration adjustments to the RH sensor: http://www.flyrodders.net/RH-Calibration.pdf Tom offers prudent advise in making any changes to your weather station: make a series of small changes (rather than a single large "home run" adjustment), waiting a reasonable interval (at least 12 hours) between all adjustments to allow for the sensor to stabilize and to assess the adjustment's impact. Tom says this about the Peet RH sensor adjustments "seems to me that I have best result creeping up on the (target) setting rather than making a big move, overshooting, and backing down. In fact I like 1/4 turn and do it over a few days... Seems to me the sponge cap needs 1/2 day to settle back after removing the cover." In other words, patience young Jeddi. I advise making any adjustments during dry conditions, if dry conditions are the predominant QC problem (generally most RH sensors can accurately measure 100% RH conditions); or wet (foggy, don't adjust sensors in the rain!) conditions if your sensor has a dry bias. As Evan says, use Phillip's (MADIS) QC statistics to diagnos the need for an RH adjustment, but use nearby calibrated ASOS dew point as a benchmark (target) observation . Consider any significant differences in elevation and proximity to water bodies between your station and the benchmark ASOS station you choose as "truth". Of course, using a sling psychrometer is an objective way of measuring dew point (taking care not to break them as some have mercury thermometers).. Dave CW0351 > > > > From bweybrecht at bellsouth.net Fri Jul 1 16:42:13 2005 From: bweybrecht at bellsouth.net (Bob) Date: Fri, 1 Jul 2005 16:42:13 -0400 Subject: [wxqc] calibrating a rain gauge In-Reply-To: <42C400A0.2030403@bridgesinn.com> Message-ID: <000001c57e7d$5cb8bdb0$0a02a8c0@wsr88d> If it's the standard, 4 inch Oregon Scientific unit, SLOWLY pouring the following amount of water through it, should give the listed results. 1 qt = 4.74in rain = 120.49mm rain 1 cup = 1.19in rain = 30.12mm rain -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of John Mulhollen Sent: Thursday, June 30, 2005 10:25 AM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] calibrating a rain gauge Without meaning to open up a can of worms (tm), what's the best way to calibrate a rain gauge? i'm thinking mine is a "bit off", as the recent rains here dumped about 3 inches into my 33 gallon trash can (with nearly vertical sides, set in the middle of the yard, much to my wife's dismay); the rain gauge registered 9mm. i'm using an oregon scientific wm918 weather system with all the stock equipment (but i added about 150 feet of category 6 cable between the sensors and the display unit). thanks! John Mulhollen CWOP1401 http://bridgesinn.com/weather/wx.htm Weather at BridgesInn.com _______________________________________________ wxqc mailing list wxqc at lists.gladstonefamily.net http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From cjfasciano at comcast.net Fri Jul 1 16:16:58 2005 From: cjfasciano at comcast.net (Christopher J. Fasciano) Date: Fri, 01 Jul 2005 20:16:58 +0000 Subject: [wxqc] made the news...correction Message-ID: <070120052016.20668.42C5A4BA0009C1CB000050BC220076106401020E070C9C0E00060C@comcast.net> Friends: I wanted to wait til we had some break in action to report minor wind damage here. We also had a wind gust of 22mph (whoopee) on a 10' pole that is raised a few feet so its up about 12-13' at most. Rain about 0.35" fell. No hail was seen. Peak rain fall rate was 2.80" by the way also. -- Christopher J. Fasciano; Latitude: 40.32N | Longitude: 79.76W, Elevation: 309 meters (1015 feet) North Huntingdon, Twp. aka Irwin, PA in the subdivion of: Circleville/Senaca Valley, in Westmoreland County Weather handles: CW2172/KPANORTH4 Dear Chris, Thanks so much for the email with the damage report. It's always good to hear from the viewers. Sincerely, Don Schwenneker WTAE Staff Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050701/fdd94166/attachment-0002.html From cjfasciano at comcast.net Fri Jul 1 16:31:10 2005 From: cjfasciano at comcast.net (Christopher J. Fasciano) Date: Fri, 01 Jul 2005 20:31:10 +0000 Subject: [wxqc] update Message-ID: <070120052031.16036.42C5A80E0000560800003EA4220076143801020E070C9C0E00060C@comcast.net> up date to the update...after showing my family the e-mail, they said we had nice branches in our yard. I would assume safely and saying medium size branches fell. Sorry for any inconvience. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pond1.gladstonefamily.net:8080/pipermail/wxqc/attachments/20050701/f90536d8/attachment-0002.html From george at prevelige.com Sat Jul 2 10:22:32 2005 From: george at prevelige.com (George Prevelige) Date: Sat, 2 Jul 2005 09:22:32 -0500 Subject: [wxqc] WeatherLink Script In-Reply-To: <200507011600.j61G0N1h028576@ns-mr6.netsolmail.com> Message-ID: <200507021423.j62ENCH9020261@ms-smtp-01-eri0.texas.rr.com> WeatherLink 5.6 adds more CWOP friendly data to its APRS upload report. However, in order for these data to be transferred, a current status window (Bulletin, Summary...) must be open. The problem: sometimes I have to restart my server remotely. I placed a shortcut of WeatherLink into my startup folder, which automatically launches WL upon reboot. But, there is no way to automatically open a current status window. Solution: I created a very simple script that sends the proper key command to WeatherLink to open the Bulletin window. I placed this script in the startup folder with the WL shortcut and the problem is solved. If anyone on this list would be interested in this script, just drop me a line and I will email it to you. Thanks, George ___________________________________ george at prevelige.com From w0lta at 4dv.net Sat Jul 2 14:30:29 2005 From: w0lta at 4dv.net (Rick Patterson) Date: Sat, 2 Jul 2005 12:30:29 -0600 Subject: [wxqc] WeatherLink Script Message-ID: Hi George, What an eligent solution. Please send me a copy of your script. Thanks, Rick w0lta >------- Original Message ------- >From : George Prevelige[mailto:george at prevelige.com] >Sent : 7/2/2005 8:22:32 AM >To : wxqc at lists.gladstonefamily.net >Cc : >Subject : RE : [wxqc] WeatherLink Script > > WeatherLink 5.6 adds more CWOP friendly data to its APRS upload report. >However, in order for these data to be transferred, a current status window >(Bulletin, Summary...) must be open. > >The problem: sometimes I have to restart my server remotely. I placed a >shortcut of WeatherLink into my startup folder, which automatically launches >WL upon reboot. But, there is no way to automatically open a current status >window. > >Solution: I created a very simple script that sends the proper key command >to WeatherLink to open the Bulletin window. I placed this script in the >startup folder with the WL shortcut and the problem is solved. > >If anyone on this list would be interested in this script, just drop me a >line and I will email it to you. > >Thanks, >George >___________________________________ >george at prevelige.com > >_______________________________________________ >wxqc mailing list >wxqc at lists.gladstonefamily.net >http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. From leaning_r at hotmail.com Sat Jul 2 22:18:31 2005 From: leaning_r at hotmail.com (Randall Richmond) Date: Sat, 02 Jul 2005 21:18:31 -0500 Subject: [wxqc] WeatherLink Script In-Reply-To: <200507021423.j62ENCH9020261@ms-smtp-01-eri0.texas.rr.com> Message-ID: Hello George: Please send me a copy of the script. Regards Randall >From: "George Prevelige" >Reply-To: Discussion of data quality issues > >To: >Subject: [wxqc] WeatherLink Script >Date: Sat, 2 Jul 2005 09:22:32 -0500 >MIME-Version: 1.0 >Received: from charon.gladstonefamily.net ([24.63.236.128]) by >mc3-f30.hotmail.com with Microsoft SMTPSVC(6.0.3790.211); Sat, 2 Jul 2005 >07:24:02 -0700 >Received: (qmail 29072 invoked by uid 10008); 2 Jul 2005 14:23:21 -0000 >Received: from localhost (HELO charon.gladstonefamily.net) (127.0.0.1) by >charon.gladstonefamily.net (qpsmtpd/0.27-dev) with ESMTP; Sat, 02 Jul 2005 >10:23:21 -0400 >Received: (qmail 29058 invoked by uid 10008); 2 Jul 2005 14:23:17 -0000 >Received: neutral (charon.gladstonefamily.net: local policy) >Received: from ms-smtp-01.texas.rr.com (HELO >ms-smtp-01-eri0.texas.rr.com)(24.93.47.40)by charon.gladstonefamily.net >(qpsmtpd/0.27-dev) with ESMTP;Sat, 02 Jul 2005 10:23:17 -0400 >Received: from junior (cpe-66-68-4-180.austin.res.rr.com [66.68.4.180])by >ms-smtp-01-eri0.texas.rr.com (8.12.10/8.12.7) with ESMTP idj62ENCH9020261 >for ;Sat, 2 Jul 2005 09:23:12 -0500 (CDT) >X-Message-Info: JGTYoYF78jHDbEfAUuEUOCgs6m20Iu2nUZfoPcu54+E= >Return-Path: >Delivered-To: mailman-wxqc at lists.gladstonefamily.net >X-Mailer: Microsoft Office Outlook, Build 11.0.6353 >X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 >Thread-Index: AcV+Vf9FBcmCdgteTjGr7z4rQ6xWIAAudg+w >X-Virus-Scanned: Symantec AntiVirus Scan Engine >X-BeenThere: wxqc at lists.gladstonefamily.net >X-Mailman-Version: 2.1.5 >Precedence: list >List-Id: Discussion of data quality issues >List-Unsubscribe: >, > >List-Archive: >List-Post: >List-Help: >List-Subscribe: >, > >Errors-To: wxqc-bounces at lists.gladstonefamily.net >X-OriginalArrivalTime: 02 Jul 2005 14:24:02.0095 (UTC) >FILETIME=[B19CEBF0:01C57F11] > > WeatherLink 5.6 adds more CWOP friendly data to its APRS upload report. >However, in order for these data to be transferred, a current status window >(Bulletin, Summary...) must be open. > >The problem: sometimes I have to restart my server remotely. I placed a >shortcut of WeatherLink into my startup folder, which automatically >launches >WL upon reboot. But, there is no way to automatically open a current status >window. > >Solution: I created a very simple script that sends the proper key command >to WeatherLink to open the Bulletin window. I placed this script in the >startup folder with the WL shortcut and the problem is solved. > >If anyone on this list would be interested in this script, just drop me a >line and I will email it to you. > >Thanks, >George >___________________________________ >george at prevelige.com > >_______________________________________________ >wxqc mailing list >wxqc at lists.gladstonefamily.net >http://pond1.gladstonefamily.net:8080/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. From mayswl at comcast.net Sun Jul 3 01:31:29 2005 From: mayswl at comcast.net (William Mays) Date: Sun, 03 Jul 2005 01:31:29 -0400 Subject: [wxqc] Over-Range Humidity data Message-ID: <5usec1hivf0uh9tl5tgnnn5j43uaqvfq7k@4ax.com> Hello; I am CW2671. Is there a fix known for use with the Oregon Scientific WM-918 and FreeWX software to avoid the huge jump in Dew Point when the data reaches 100%RH and goes into Over-Range? That appears to be the cause of an apparent drop of ~60F in dew point. Recently, I have set the FreeWX parameter Offset: OHum=+6.1 in an attempt to improve calibration. The benefit is not yet proven, might this be an issue for the reported data indicating >100%RH? Are the units of OHum offset known? (dew point F, C; %RH?, grains of H2O per ton of air?) Relocation and shielding of the T & H sensor has improved the Temp data over the last week or so. Thanks; Bill -- Bill Mays Cinnaminson, NJ 08077 NEW EMAIL: mayswl at comcast.net OLD: mayswl at uscom.com Texas: AH-HS'61, UT-Austin'66; Moorestown, NJ: RCA, GE, MM, Lockheed Martin From clayj at nwlink.com Sun Jul 10 01:58:47 2005 From: clayj at nwlink.com (Clay Jackson) Date: Sat, 9 Jul 2005 22:58:47 -0700 Subject: [wxqc] Davis Humidity Issue In-Reply-To: <002201c57779$0a8fc6b0$628a3243@MARKSCOMPAQ> References: <200506220853343.SM00652@markamd2003> <002201c57779$0a8fc6b0$628a3243@MARKSCOMPAQ> Message-ID: I've got a Davis WMII - and the humidity sensor has started acting up. It's consistently reading about 5% high, which translates to a dew point error of several degrees - outside the QC range. The sensor is about 6' AGL on a mast that's about 15' from the side of our house; on a Davis platform/shield. The mast sits in the middle of a garden that currently only has a few rose bushes in it and is NOT overly watered (drip system); and in fact it's had no 'extra' water used this season (we're averaging just under 1" of rain/ week here outside Seattle. The nearest foliage is about 8' from the base of the sensor shield, so I don't THINK that should make a difference. I'm going to go out tomorrow and dismount and clean the sensor (compressed air blast). Anyone got any ideas other than that? I suppose I could "hook" my recording program (meteo) to subtract 5% from the RH, but that's kind of a drag.... Clay Jackson From James.Dudley at noaa.gov Sun Jul 10 20:34:59 2005 From: James.Dudley at noaa.gov (James Dudley) Date: Sun, 10 Jul 2005 17:34:59 -0700 Subject: [wxqc] Davis Humidity Issue Message-ID: Clay, I too have had issues with my trusty old WMII, where the relative humidity will "behave" for a long period of time and then seemingly either jump up or down by a few percent and then stay "stuck" at this new level of callibration. I did take my temp/rh sensor apart and clean it out however the readings didn't change. I just gave up and "adjusted" the calibration on the Davis unit to read back to the old level. The unit has been behaving nicely at its new calibration level. Still don't know why the calibration changed in the first place? Jim Dudley CW2553 Hanford CA ----- Original Message ----- From: Clay Jackson Date: Saturday, July 9, 2005 10:58 pm Subject: [wxqc] Davis Humidity Issue > I've got a Davis WMII - and the humidity sensor has started acting > > up. It's consistently reading about 5% high, which translates to > a > dew point error of several degrees - outside the QC range. > > The sensor is about 6' AGL on a mast that's about 15' from the > side > of