From cwop at adobe-labs.com Sat Sep 1 20:03:13 2007 From: cwop at adobe-labs.com (Brent Gordon) Date: Sat, 01 Sep 2007 19:03:13 -0600 Subject: [wxqc] Station Change for CW8328 Message-ID: <46DA0BD1.30606@adobe-labs.com> Effective 9/1/2007 2355 UTC the location of my anemometer changed from 6 feet above ground level to approximately 19 feet AGL. The anemometer is also approximately 15 feet south of its previous location. The location for the rest of the sensor suite is unchanged. The new location puts the anemometer slightly higher than the top of my roof line. Brent Gordon CW8328 http://www.findu.com/cgi-bin/wxpage.cgi?last=24&call=cw8328 http://raws.wrh.noaa.gov/cgi-bin/roman/meso_base.cgi?stn=c8328&unit=0&time=LOCAL http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KNMALBUQ51 From brillig at gmail.com Sat Sep 1 21:18:38 2007 From: brillig at gmail.com (Victor Engel) Date: Sat, 1 Sep 2007 21:18:38 -0500 Subject: [wxqc] Named Bat Storm Message-ID: Just noticed on the Seguin radar, as reported by weatherunderground.com that the bats emerging just north of San Antonio has been named A3. Such statistics as 3 Kg/square meter VIL, speed of 27 knots, top of 1000 feet were listed for a while. I've seen bats on radar before. That's a daily occurrence. This is the first time I've seen a bat swarm actually "named" this way. Victor From gerry.creager at tamu.edu Sat Sep 1 22:50:50 2007 From: gerry.creager at tamu.edu (Gerry Creager) Date: Sat, 01 Sep 2007 22:50:50 -0500 Subject: [wxqc] Named Bat Storm In-Reply-To: References: Message-ID: <46DA331A.2020007@tamu.edu> Typically, the EWX radar sees the bats emerging from downtown Austin on a daily basis. Victor Engel wrote: > Just noticed on the Seguin radar, as reported by > weatherunderground.com that the bats emerging just north of San > Antonio has been named A3. Such statistics as 3 Kg/square meter VIL, > speed of 27 knots, top of 1000 feet were listed for a while. > > I've seen bats on radar before. That's a daily occurrence. This is the > first time I've seen a bat swarm actually "named" this way. > > Victor > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -- Gerry Creager -- gerry.creager at tamu.edu Texas Mesonet -- AATLT, Texas A&M University Cell: 979.229.5301 Office: 979.862.3982 FAX: 979.862.3983 Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843 From brillig at gmail.com Sat Sep 1 23:18:21 2007 From: brillig at gmail.com (Victor Engel) Date: Sat, 1 Sep 2007 23:18:21 -0500 Subject: [wxqc] Named Bat Storm In-Reply-To: <46DA331A.2020007@tamu.edu> References: <46DA331A.2020007@tamu.edu> Message-ID: On 9/1/07, Gerry Creager wrote: > Typically, the EWX radar sees the bats emerging from downtown Austin on > a daily basis. > True. And Round Rock, and north of San Antonio, and usually at least half a dozen other spots around the region. What was unusual this time was that the storm tracker named and tracked it. If that happens regularly, I've not seen it before. Victor From gerry.creager at tamu.edu Sun Sep 2 09:03:08 2007 From: gerry.creager at tamu.edu (Gerry Creager) Date: Sun, 02 Sep 2007 09:03:08 -0500 Subject: [wxqc] Named Bat Storm In-Reply-To: References: <46DA331A.2020007@tamu.edu> Message-ID: <46DAC29C.3050202@tamu.edu> Part of this depends on what mode the radar is in. For the WSR-88D's you shouldn't see "storm" tracking of biologials in clear air mode. In storm mode, it does happen. gerry Victor Engel wrote: > On 9/1/07, Gerry Creager wrote: >> Typically, the EWX radar sees the bats emerging from downtown Austin on >> a daily basis. >> > > True. And Round Rock, and north of San Antonio, and usually at least > half a dozen other spots around the region. What was unusual this time > was that the storm tracker named and tracked it. If that happens > regularly, I've not seen it before. > > Victor > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -- Gerry Creager -- gerry.creager at tamu.edu Texas Mesonet -- AATLT, Texas A&M University Cell: 979.229.5301 Office: 979.862.3982 FAX: 979.862.3983 Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843 From m47 at mac.com Tue Sep 4 22:36:10 2007 From: m47 at mac.com (Tim) Date: Tue, 4 Sep 2007 23:36:10 -0400 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) Message-ID: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> Hello all, I have had a davis weather station for about a week now and one thing I've noticed is that every night at about 10 - 11 am the temperature rises 1/2 a degree or so (sometimes more). I realize this is an extremely small amount but it seems to be happening consistently and across multiple stations in my area (though I only confirmed the phenomenon at multiple sites for one night). A graph that shows it well is at: http://tjl.dyndns.org:81/weather/test1.php? field1=Temperature&field2=Dewpoint&zoom=yes&date=09/04/07&history=true&p eriod=Daily (the faded lines are yesterday's data) regards, Tim APRS: c8595 Wunderground: KFLTAMPA53 From paulgrace at lookoutranch.com Tue Sep 4 23:50:50 2007 From: paulgrace at lookoutranch.com (Paul Grace) Date: Tue, 4 Sep 2007 21:50:50 -0700 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) In-Reply-To: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> References: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> Message-ID: <004d01c7ef78$55561f90$0200a8c0@dell1500> If you enclose log URLs with angle brackets <> then most mail clients will interpret them as HTML tags and leave them whole. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Tim Sent: Tuesday, September 04, 2007 20:36 To: wxqc at lists.gladstonefamily.net Subject: [wxqc] slight but unexplained temperature anomaly (c8595) Hello all, I have had a davis weather station for about a week now and one thing I've noticed is that every night at about 10 - 11 am the temperature rises 1/2 a degree or so (sometimes more). I realize this is an extremely small amount but it seems to be happening consistently and across multiple stations in my area (though I only confirmed the phenomenon at multiple sites for one night). A graph that shows it well is at: http://tjl.dyndns.org:81/weather/test1.php? field1=Temperature&field2=Dewpoint&zoom=yes&date=09/04/07&history=true&p eriod=Daily (the faded lines are yesterday's data) regards, Tim APRS: c8595 Wunderground: KFLTAMPA53 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From brillig at gmail.com Tue Sep 4 23:46:36 2007 From: brillig at gmail.com (Victor Engel) Date: Tue, 4 Sep 2007 23:46:36 -0500 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) In-Reply-To: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> References: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> Message-ID: I assume you mean PM? On 9/4/07, Tim wrote: > Hello all, > I have had a davis weather station for about a week now and one thing > I've noticed is that every night at about 10 - 11 am the temperature > rises 1/2 a degree or so (sometimes more). I realize this is an > extremely small amount but it seems to be happening consistently and > across multiple stations in my area (though I only confirmed the > phenomenon at multiple sites for one night). A graph that shows it > well is at: > > http://tjl.dyndns.org:81/weather/test1.php?field1=Temperature&field2=Dewpoint&zoom=yes&date=09/04/07&history=true&period=Daily > > (the faded lines are yesterday's data) > > regards, > Tim > APRS: c8595 > Wunderground: KFLTAMPA53 > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From bweybrecht at bellsouth.net Wed Sep 5 06:09:53 2007 From: bweybrecht at bellsouth.net (Bob) Date: Wed, 5 Sep 2007 07:09:53 -0400 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) In-Reply-To: <004d01c7ef78$55561f90$0200a8c0@dell1500> Message-ID: <003401c7efad$49823840$6f5a210a@wsr88d> -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Paul Grace Sent: Wednesday, September 05, 2007 12:51 AM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] slight but unexplained temperature anomaly (c8595) If you enclose log URLs with angle brackets <> then most mail clients will interpret them as HTML tags and leave them whole. Tinyurl.com works too.. http://tinyurl.com/29de7y From dshelms at comcast.net Wed Sep 5 07:09:43 2007 From: dshelms at comcast.net (Dave Helms) Date: Wed, 05 Sep 2007 08:09:43 -0400 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) In-Reply-To: References: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> Message-ID: <46DE9C87.1070608@comcast.net> Hi Tim, My best guess is the timing of the temperature is just a coincidence in this case. As you cool down for the down, especially for stations aways from the coast, evening radiational cooling occurs. This surface temperature inversion grows (e.g. the difference between the surface temperature and the temperature at the top of the inversion) through the night through about 05L (varies by date of year). Here is a vertical profile from the Tampa radiosonde two days ago as an example: http://raob.fsl.noaa.gov/intl/skewt/skewt.cgi?file=temp/TBW-72210-03-SEP-2007-12UTC&wmo=72210 * Note the red temperature line moves from left to right as you go up from the bottom of the chart, warming from about 23C at the surface to about 26C just above the surface (a few hundred feet) With this weak summer inversion, any little wind gust/turbulence above the inversion can "mix out" the inversion and cause warmer air to descend to the surface which will raise your temperature. Looking at your station time series in FINDU: http://www.findu.com/cgi-bin/wxpage.cgi?call=cw8595&last=120 ... You have had several thunderstorms and rainshowers in your location, indicated by the recent rainfall, which are the likely cause of the turbulence which perturbed the weak radiation inversion, which raised your temperature. When you see your temperature increasing at night, always also check your winds. 9 times out of 10 the winds will be peaking about the same time as the nocternal temperature increase. Dave CW0351 Victor Engel wrote: >I assume you mean PM? > >On 9/4/07, Tim wrote: > > >>Hello all, >>I have had a davis weather station for about a week now and one thing >>I've noticed is that every night at about 10 - 11 am the temperature >>rises 1/2 a degree or so (sometimes more). I realize this is an >>extremely small amount but it seems to be happening consistently and >>across multiple stations in my area (though I only confirmed the >>phenomenon at multiple sites for one night). A graph that shows it >>well is at: >> >>http://tjl.dyndns.org:81/weather/test1.php?field1=Temperature&field2=Dewpoint&zoom=yes&date=09/04/07&history=true&period=Daily >> >>(the faded lines are yesterday's data) >> >>regards, >>Tim >>APRS: c8595 >>Wunderground: KFLTAMPA53 >>_______________________________________________ >>wxqc mailing list >>Post messages to wxqc at lists.gladstonefamily.net >>To unsubcribe or change delivery options, please go to: >>http://server.gladstonefamily.net/mailman/listinfo/wxqc >> >>The contents of this message are the responsibility of the author. >> >> >> >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > > > > From webmaster at memphisweather.net Wed Sep 5 06:26:34 2007 From: webmaster at memphisweather.net (Erik Proseus) Date: Wed, 5 Sep 2007 06:26:34 -0500 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) In-Reply-To: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> References: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> Message-ID: Tim, One thing I would look at is a plot of windspeed as well. I'm in a suburb of Memphis but far enough out that I don't get the heat island. My overnight temps seem to be closely tied to wind and it isn't uncommon for the temp to rise slightly on a calm night if the wind picks up to a couple of mph. Looking at your WU data for 9/4, I see no wind after about 9:15, then a "gust" of about 3 mph at the same time your temp rises. I'll bet the wind mixed the air around your station just enough to see the slight rise. It doesn't take much. --Erik ------------------- Erik Proseus, C4427 MemphisWeather.Net KTNBARTL6 -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Tim Sent: Tuesday, September 04, 2007 10:36 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] slight but unexplained temperature anomaly (c8595) Hello all, I have had a davis weather station for about a week now and one thing I've noticed is that every night at about 10 - 11 am the temperature rises 1/2 a degree or so (sometimes more). I realize this is an extremely small amount but it seems to be happening consistently and across multiple stations in my area (though I only confirmed the phenomenon at multiple sites for one night). A graph that shows it well is at: http://tjl.dyndns.org:81/weather/test1.php? field1=Temperature&field2=Dewpoint&zoom=yes&date=09/04/07&history=true&p eriod=Daily (the faded lines are yesterday's data) regards, Tim APRS: c8595 Wunderground: KFLTAMPA53 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From slottech at gbis.com Wed Sep 5 08:27:43 2007 From: slottech at gbis.com (Richard) Date: Wed, 5 Sep 2007 06:27:43 -0700 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) In-Reply-To: <003401c7efad$49823840$6f5a210a@wsr88d> References: <004d01c7ef78$55561f90$0200a8c0@dell1500> <003401c7efad$49823840$6f5a210a@wsr88d> Message-ID: <040601c7efc0$8aac3790$0501a8c0@Richardn> Or you can do it the easy way by copying the broken URL into Notepad, put it back together, then copy it into Internet Explorer. Richard www.n7tgb.net -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bob Sent: Wednesday, September 05, 2007 4:10 AM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] slight but unexplained temperature anomaly (c8595) -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Paul Grace Sent: Wednesday, September 05, 2007 12:51 AM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] slight but unexplained temperature anomaly (c8595) If you enclose log URLs with angle brackets <> then most mail clients will interpret them as HTML tags and leave them whole. Tinyurl.com works too.. http://tinyurl.com/29de7y _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From hatkin at cebridge.net Wed Sep 5 08:55:12 2007 From: hatkin at cebridge.net (Hubert Atkinson) Date: Wed, 5 Sep 2007 08:55:12 -0500 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) References: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> <46DE9C87.1070608@comcast.net> Message-ID: <003401c7efc4$61e38e40$6401a8c0@Hubert> FWIW: I have a LaCrosse 2315. For some time after I set it up, I was having a problem with temperature "spikes". I happen to have some of that aluminized "bubble wrap" insulation on hand, and I wrapped the sensor housing (just a plastic cup affair) with the insulation. That eliminated most of the big swings, and gave a much more uniform reading. Hubert (CW8464) ----- Original Message ----- From: "Dave Helms" To: "Discussion of weather data quality issues" Sent: Wednesday, September 05, 2007 7:09 AM Subject: Re: [wxqc] slight but unexplained temperature anomaly (c8595) > Hi Tim, > > My best guess is the timing of the temperature is just a coincidence in > this case. As you cool down for the down, especially for stations aways > from the coast, evening radiational cooling occurs. This surface > temperature inversion grows (e.g. the difference between the surface > temperature and the temperature at the top of the inversion) through the > night through about 05L (varies by date of year). Here is a vertical > profile from the Tampa radiosonde two days ago as an example: > http://raob.fsl.noaa.gov/intl/skewt/skewt.cgi?file=temp/TBW-72210-03-SEP-2007-12UTC&wmo=72210 > * Note the red temperature line moves from left to right as you go up > from the bottom of the chart, warming from about 23C at the surface to > about 26C just above the surface (a few hundred feet) > > With this weak summer inversion, any little wind gust/turbulence above > the inversion can "mix out" the inversion and cause warmer air to > descend to the surface which will raise your temperature. Looking at > your station time series in FINDU: > http://www.findu.com/cgi-bin/wxpage.cgi?call=cw8595&last=120 > > ... You have had several thunderstorms and rainshowers in your location, > indicated by the recent rainfall, which are the likely cause of the > turbulence which perturbed the weak radiation inversion, which raised > your temperature. When you see your temperature increasing at night, > always also check your winds. 9 times out of 10 the winds will be > peaking about the same time as the nocternal temperature increase. > > Dave > CW0351 > > Victor Engel wrote: > >>I assume you mean PM? >> >>On 9/4/07, Tim wrote: >> >> >>>Hello all, >>>I have had a davis weather station for about a week now and one thing >>>I've noticed is that every night at about 10 - 11 am the temperature >>>rises 1/2 a degree or so (sometimes more). I realize this is an >>>extremely small amount but it seems to be happening consistently and >>>across multiple stations in my area (though I only confirmed the >>>phenomenon at multiple sites for one night). A graph that shows it >>>well is at: >>> >>>http://tjl.dyndns.org:81/weather/test1.php?field1=Temperature&field2=Dewpoint&zoom=yes&date=09/04/07&history=true&period=Daily >>> >>>(the faded lines are yesterday's data) >>> >>>regards, >>>Tim >>>APRS: c8595 >>>Wunderground: KFLTAMPA53 >>>_______________________________________________ >>>wxqc mailing list >>>Post messages to wxqc at lists.gladstonefamily.net >>>To unsubcribe or change delivery options, please go to: >>>http://server.gladstonefamily.net/mailman/listinfo/wxqc >>> >>>The contents of this message are the responsibility of the author. >>> >>> >>> >>_______________________________________________ >>wxqc mailing list >>Post messages to wxqc at lists.gladstonefamily.net >>To unsubcribe or change delivery options, please go to: >>http://server.gladstonefamily.net/mailman/listinfo/wxqc >> >>The contents of this message are the responsibility of the author. >> >> >> >> > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From m47 at mac.com Tue Sep 4 22:36:10 2007 From: m47 at mac.com (Tim) Date: Tue, 4 Sep 2007 23:36:10 -0400 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) Message-ID: <4390CF1E-8D37-46F6-9589-A67168F9FC64@mac.com> Thanks for the the explanations (and the tip about URL's!) the winds have seemed completely calm but I'll definitely check for them. Thanks, Dave, for the skew-t link this is very nice to have. regards, Tim APRS: c8595 Wunderground: KFLTAMPA53 From paulgrace at lookoutranch.com Wed Sep 5 12:25:45 2007 From: paulgrace at lookoutranch.com (Paul Grace) Date: Wed, 5 Sep 2007 10:25:45 -0700 Subject: [wxqc] OT: TinyURL RE: slight but unexplained temperature anomaly (c8595) In-Reply-To: <003401c7efad$49823840$6f5a210a@wsr88d> References: <004d01c7ef78$55561f90$0200a8c0@dell1500> <003401c7efad$49823840$6f5a210a@wsr88d> Message-ID: <00e701c7efe1$cb520a60$0200a8c0@dell1500> I mentioned TinyURL here before, and I got some notes back that some sites ban it because it can't be parsed by users. Note that TinyURL now has a "preview" cookie you can set so that you are shown the URL before you decide to go. Also note: TinyURL.com/dick takes you to the Vice-President's office. I discovered other words that take you to other humorous (IMO) locations. Those words shall not be published here by me. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Bob Sent: Wednesday, September 05, 2007 04:10 To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] slight but unexplained temperature anomaly (c8595) -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Paul Grace Sent: Wednesday, September 05, 2007 12:51 AM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] slight but unexplained temperature anomaly (c8595) If you enclose log URLs with angle brackets <> then most mail clients will interpret them as HTML tags and leave them whole. Tinyurl.com works too.. http://tinyurl.com/29de7y _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From Djeerings at tampabay.rr.com Wed Sep 5 12:15:14 2007 From: Djeerings at tampabay.rr.com (Don Jeerings) Date: Wed, 5 Sep 2007 13:15:14 -0400 Subject: [wxqc] time of temperature change. D jeerings Message-ID: <000e01c7efe0$530ef370$6401a8c0@donscomputer> Your comment.. I have had a davis weather station for about a week now and one thing I've noticed is that every night at about 10 - 11 am the temperature rises 1/2 a degree or so (sometimes more). Here in Florida I see changes in land and ocean breeze direction and temperature around 10 to 11 PM. Snakers -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070905/4cba5596/attachment.html From m47 at mac.com Wed Sep 5 15:20:32 2007 From: m47 at mac.com (Tim) Date: Wed, 5 Sep 2007 16:20:32 -0400 Subject: [wxqc] time of temperature change. D jeerings Message-ID: <188B102E-D1B0-446A-8671-7A568B118712@mac.com> > Here in Florida I see changes in land and ocean breeze direction and temperature around 10 to 11 PM. > > Snakers > I just noticed I wrote 10-11 am. I did mean pm. I didn't think about the sea breeze, that would make sense. From Weather at pdfamily.com Fri Sep 7 19:02:55 2007 From: Weather at pdfamily.com (Milford Weather) Date: Fri, 7 Sep 2007 20:02:55 -0400 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) In-Reply-To: <11C5A59A-458D-4715-80D1-757B62969C52@mac.com> Message-ID: <200709080002.l8802tg28424@plus41.host4u.net> I have had my VP2 for a few years now and frequently have a similar event, except mine usually occurs around 3-4am. I live about 90% of the way up a long hill above a valley and my theory is that, when the valley has filled with cool air to a certain point, that a "slug" of warm air is displaced up the hill and past my station. The only other theory that seems plausible it what someone else has mentioned with the wind and mixing, but evaluating my own situation, the data doesn't seem to support that. On the other hand, both could be wrong. Paul CW3414 SkyWarn Spotter http:/www.PDfamily.com/weather -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Tim Sent: Tuesday, September 04, 2007 11:36 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] slight but unexplained temperature anomaly (c8595) Hello all, I have had a davis weather station for about a week now and one thing I've noticed is that every night at about 10 - 11 am the temperature rises 1/2 a degree or so (sometimes more). I realize this is an extremely small amount but it seems to be happening consistently and across multiple stations in my area (though I only confirmed the phenomenon at multiple sites for one night). A graph that shows it well is at: http://tjl.dyndns.org:81/weather/test1.php? field1=Temperature&field2=Dewpoint&zoom=yes&date=09/04/07&history=true&p eriod=Daily (the faded lines are yesterday's data) regards, Tim APRS: c8595 Wunderground: KFLTAMPA53 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070907/f3ef253c/attachment-0001.html -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 2356 bytes Desc: not available Url : http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070907/f3ef253c/attachment-0001.gif From miklah at charter.net Sat Sep 8 06:59:40 2007 From: miklah at charter.net (Mike Y) Date: Sat, 8 Sep 2007 07:59:40 -0400 Subject: [wxqc] slight but unexplained temperature anomaly (c8595) References: <200709080002.l8802tg28424@plus41.host4u.net> Message-ID: <003201c7f20f$bd8b4240$6500a8c0@MikesT23> I wonder... could it be a weather station issue? Perhaps there's a schedule where the local power company changes power factor on the line and somehow that is getting through the power supply in the weather stations and affecting things. ----- Original Message ----- From: "Milford Weather" To: "'Discussion of weather data quality issues'" Sent: Friday, September 07, 2007 8:02 PM Subject: Re: [wxqc] slight but unexplained temperature anomaly (c8595) > I have had my VP2 for a few years now and frequently have a similar event, > except mine usually occurs around 3-4am. I live about 90% of the way up a > long hill above a valley and my theory is that, when the valley has filled > with cool air to a certain point, that a "slug" of warm air is displaced up > the hill and past my station. The only other theory that seems plausible it > what someone else has mentioned with the wind and mixing, but evaluating my > own situation, the data doesn't seem to support that. > > On the other hand, both could be wrong. > > > > Paul > > > > CW3414 > > SkyWarn Spotter > > http:/www.PDfamily.com/weather > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Tim > Sent: Tuesday, September 04, 2007 11:36 PM > To: wxqc at lists.gladstonefamily.net > Subject: [wxqc] slight but unexplained temperature anomaly (c8595) > > > > Hello all, > > I have had a davis weather station for about a week now and one thing > > I've noticed is that every night at about 10 - 11 am the temperature > > rises 1/2 a degree or so (sometimes more). I realize this is an > > extremely small amount but it seems to be happening consistently and > > across multiple stations in my area (though I only confirmed the > > phenomenon at multiple sites for one night). A graph that shows it > > well is at: > > > > http://tjl.dyndns.org:81/weather/test1.php? > > field1=Temperature&field2=Dewpoint&zoom=yes&date=09/04/07&history=true&p > > eriod=Daily > > > > (the faded lines are yesterday's data) > > > > regards, > > Tim > > APRS: c8595 > > Wunderground: KFLTAMPA53 > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ---------------------------------------------------------------------------- ---- > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From dwyer at nspktrgdgt.com Sat Sep 8 16:44:07 2007 From: dwyer at nspktrgdgt.com (dwyer at nspktrgdgt.com) Date: Sat, 8 Sep 2007 14:44:07 -0700 Subject: [wxqc] Unusual temperature data in QC charts Message-ID: <20070908214407.GA18065@starbase2> As of about 20:00Z on 9/05/07, when it appears QC analysis of my station was enabled, the reported temperature data on the QC charts shows up very strangely. It shows a regular oscillation of ~5 degrees between each observation. However, the data on findu.com and MADIS does not show this feature. http://weather.gladstonefamily.net/site/C8688 I am not sure if this is a problem on my end or not, but it is causing the temperature data to fail validation checks (although MADIS is happy). Has this been seen before? Is it a known problem? Thanks... -f From gerry.creager at tamu.edu Sun Sep 9 07:34:08 2007 From: gerry.creager at tamu.edu (Gerry Creager) Date: Sun, 09 Sep 2007 07:34:08 -0500 Subject: [wxqc] Unusual temperature data in QC charts In-Reply-To: <20070908214407.GA18065@starbase2> References: <20070908214407.GA18065@starbase2> Message-ID: <46E3E840.7020804@tamu.edu> How frequent are your updates? MADIS gets data on a 15 minute cycle although that could change to a 5 minute cycle. What hardware are you using and where is your temperature sensor located... and how is it constructed? Is it aspirated, and is it in a decent radiation shield? Lots of questions, but they may help answer the original question. gerry dwyer at nspktrgdgt.com wrote: > As of about 20:00Z on 9/05/07, when it appears QC analysis of my station was enabled, > the reported temperature data on the QC charts shows up very strangely. It shows > a regular oscillation of ~5 degrees between each observation. However, the data on > findu.com and MADIS does not show this feature. > > http://weather.gladstonefamily.net/site/C8688 > > I am not sure if this is a problem on my end or not, but it is causing the > temperature data to fail validation checks (although MADIS is happy). Has > this been seen before? Is it a known problem? > > Thanks... > > -f > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -- Gerry Creager -- gerry.creager at tamu.edu Texas Mesonet -- AATLT, Texas A&M University Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983 Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843 From philip at gladstonefamily.net Sun Sep 9 09:14:24 2007 From: philip at gladstonefamily.net (Philip Gladstone) Date: Sun, 09 Sep 2007 10:14:24 -0400 Subject: [wxqc] Unusual temperature data in QC charts In-Reply-To: <20070908214407.GA18065@starbase2> References: <20070908214407.GA18065@starbase2> Message-ID: <46E3FFC0.8060506@gladstonefamily.net> dwyer at nspktrgdgt.com wrote: > As of about 20:00Z on 9/05/07, when it appears QC analysis of my station was enabled, > the reported temperature data on the QC charts shows up very strangely. It shows > a regular oscillation of ~5 degrees between each observation. However, the data on > findu.com and MADIS does not show this feature. > > http://weather.gladstonefamily.net/site/C8688 > > I am not sure if this is a problem on my end or not, but it is causing the > temperature data to fail validation checks (although MADIS is happy). Has > this been seen before? Is it a known problem? > > > This is an artifact caused by you changing your registered elevation. It will persist until MADIS picks up the new station data file on tuesday/wednesday next week. The explanation is that the temperature readings that I get from MADIS are not station temperature, but are adjusted for elevation. Unfortunately, for this period of time, MADIS and I have different ideas of the elevation...... Philip From m47 at mac.com Sun Sep 9 17:23:16 2007 From: m47 at mac.com (Tim) Date: Sun, 9 Sep 2007 18:23:16 -0400 Subject: [wxqc] Pole for wind gauge revisited Message-ID: <78667338-7C4C-4425-A31C-63A3ADB58D3D@mac.com> I was browsing through the thread from June "Pole for wind gauge" which was very informative. One thing I have been trying to figure out, I have a antenna pole stuck in the ground and mounted to the side of the roof. What does anyone think is the best pole material and maximum unguyed height for this type of installation? Guying simply is not in option on the cramped property I'm using. Regards, Tim CW8595 From jimwc at frontiernet.net Sun Sep 9 22:57:58 2007 From: jimwc at frontiernet.net (Jim) Date: Sun, 9 Sep 2007 20:57:58 -0700 Subject: [wxqc] Pole for wind gauge revisited In-Reply-To: <78667338-7C4C-4425-A31C-63A3ADB58D3D@mac.com> References: <78667338-7C4C-4425-A31C-63A3ADB58D3D@mac.com> Message-ID: <000901c7f35e$c70c83b0$55258b10$@net> Tim I use galvanized Electrical conduit instead of "antenna" pole. The wall thickness is a little thicker and the price is about the same. I have used a 10' section with a chimney mount which puts the anemometer between 5-6 ft. above the peek of the roof, and it has withstood 40-45 mph winds. You can see pictures on my QC report. If you don't have a chimney I would suggest mounting with the pole in the ground (maybe in a chunk of concrete for a anchor) so that it comes up at the peek and secure the pole with a "U" bracket to the eve of the roof at the peek. There are couplers available to connect pieces of conduit together so you can get the correct height. The instructions that came with my anemometer suggested 3 feet above the peek of the roof I tried to double that. Something to be aware of is metal poles have an effect on the magnets of the anemometer so you may also want to adapt the top to a 1 foot piece of PVC pipe (I used a 1" X 1' PVC nipple) to mount the anemometer on. All materials are available at home depot, Lowes, etc. Jim CW4367 -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Tim Sent: Sunday, September 09, 2007 3:23 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Pole for wind gauge revisited I was browsing through the thread from June "Pole for wind gauge" which was very informative. One thing I have been trying to figure out, I have a antenna pole stuck in the ground and mounted to the side of the roof. What does anyone think is the best pole material and maximum unguyed height for this type of installation? Guying simply is not in option on the cramped property I'm using. Regards, Tim CW8595 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From sullivan238 at cox.net Sun Sep 9 23:08:06 2007 From: sullivan238 at cox.net (Jim Sullivan) Date: Sun, 9 Sep 2007 21:08:06 -0700 Subject: [wxqc] Pole for wind gauge revisited In-Reply-To: <78667338-7C4C-4425-A31C-63A3ADB58D3D@mac.com> Message-ID: You didn't state the diameter of this pole, or the length past the last mount point. That's what determines the strength. The wind instrument is very light, it has a small wind profile, so you can get away with a 1-1/4 steel pole, maybe 20 feet of unsupported length. This will likely be OK up to 40 mph gusts. Get a larger diameter if the winds are worse. Jim Sullivan -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Tim Sent: Sunday, September 09, 2007 15:23 To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Pole for wind gauge revisited I was browsing through the thread from June "Pole for wind gauge" which was very informative. One thing I have been trying to figure out, I have a antenna pole stuck in the ground and mounted to the side of the roof. What does anyone think is the best pole material and maximum unguyed height for this type of installation? Guying simply is not in option on the cramped property I'm using. Regards, Tim CW8595 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From jimwc at frontiernet.net Mon Sep 10 09:25:36 2007 From: jimwc at frontiernet.net (Jim) Date: Mon, 10 Sep 2007 07:25:36 -0700 Subject: [wxqc] Pole for wind gauge revisited In-Reply-To: References: <78667338-7C4C-4425-A31C-63A3ADB58D3D@mac.com> Message-ID: <000001c7f3b6$74e1c8e0$5ea55aa0$@net> Jim & Tim I am using 1-1/4" Electrical conduit and the unsupported length is about 6-7 feet. Jim CW4367 -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Jim Sullivan Sent: Sunday, September 09, 2007 9:08 PM To: Discussion of weather data quality issues Subject: Re: [wxqc] Pole for wind gauge revisited You didn't state the diameter of this pole, or the length past the last mount point. That's what determines the strength. The wind instrument is very light, it has a small wind profile, so you can get away with a 1-1/4 steel pole, maybe 20 feet of unsupported length. This will likely be OK up to 40 mph gusts. Get a larger diameter if the winds are worse. Jim Sullivan -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Tim Sent: Sunday, September 09, 2007 15:23 To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Pole for wind gauge revisited I was browsing through the thread from June "Pole for wind gauge" which was very informative. One thing I have been trying to figure out, I have a antenna pole stuck in the ground and mounted to the side of the roof. What does anyone think is the best pole material and maximum unguyed height for this type of installation? Guying simply is not in option on the cramped property I'm using. Regards, Tim CW8595 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From m47 at mac.com Mon Sep 10 09:17:28 2007 From: m47 at mac.com (Tim) Date: Mon, 10 Sep 2007 10:17:28 -0400 Subject: [wxqc] Pole for wind gauge revisited In-Reply-To: References: Message-ID: <938D9770-0C49-438F-B617-7043E9AFED6D@mac.com> The diameter is 1.25" 16 gauge steel, the kind found at radio shack. The mount point is about 8 feet, firmly affixed to studs in the roof eave with a U bolt. The radio shack masting seems to me to have a low weight to rigidity ratio. So as another poster mention I'll look into electrical conduit. ...Aluminum seems like it would be a better material. On Sep 10, 2007, at 12:08 AM, Jim Sullivan wrote: > You didn't state the diameter of this pole, or the length past the > last > mount point. That's what determines the strength. The wind > instrument is > very light, it has a small wind profile, so you can get away with a > 1-1/4 > steel pole, maybe 20 feet of unsupported length. This will likely > be OK up > to 40 mph gusts. Get a larger diameter if the winds are worse. > > Jim Sullivan > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Tim > Sent: Sunday, September 09, 2007 15:23 > To: wxqc at lists.gladstonefamily.net > Subject: [wxqc] Pole for wind gauge revisited > > > I was browsing through the thread from June "Pole for wind gauge" > which was very informative. One thing I have been trying to figure > out, I have a antenna pole stuck in the ground and mounted to the > side of the roof. What does anyone think is the best pole material > and maximum unguyed height for this type of installation? Guying > simply is not in option on the cramped property I'm using. > > Regards, Tim > CW8595 > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From brillig at gmail.com Mon Sep 10 10:24:50 2007 From: brillig at gmail.com (Victor Engel) Date: Mon, 10 Sep 2007 10:24:50 -0500 Subject: [wxqc] Pole for wind gauge revisited In-Reply-To: <938D9770-0C49-438F-B617-7043E9AFED6D@mac.com> References: <938D9770-0C49-438F-B617-7043E9AFED6D@mac.com> Message-ID: The pole I use currently is an adjustable 8-16 foot pole designed to be used for swimming pool nets. It has a corrugated profile and is very light. I have it extended part way so that the anemometer is 12 feet above the peak of my roof, giving a height of 40 feet (I have a 2 storey house). So far I've had no problems with it unguyed, but it does sway in strong winds. Victor On 9/10/07, Tim wrote: > The diameter is 1.25" 16 gauge steel, the kind found at radio shack. > The mount point is about 8 feet, firmly affixed to studs in the roof > eave with a U bolt. The radio shack masting seems to me to have a low > weight to rigidity ratio. So as another poster mention I'll look into > electrical conduit. ...Aluminum seems like it would be a better > material. > From webmaster at farmingtonweather.com Mon Sep 10 14:08:58 2007 From: webmaster at farmingtonweather.com (webmaster) Date: Mon, 10 Sep 2007 14:08:58 -0500 Subject: [wxqc] wxqc Digest, Vol 35, Issue 4 In-Reply-To: References: Message-ID: <20070910190934.D819418019C@relay02.roch.ny.frontiernet.net> When searching for a way to mount my weather station and anemometer I did a fair amount of research on various kinds of masts, mostly used for antennae installations. Hy-Gain makes an antennae mast that can be extended to about 60 feet and they say it can be used up to 30' without guy wires. I evaluated the pipes and thicknesses of them and determined that I could make an even stronger mast using SCH-40 aluminum pipe. I have double the wall thickness and a larger diameter. A local scrap dealer sells the pipe at scrap price so the pipes were pretty cheap relative to buying a mast like the Hy-gain model. I cemented a 2.5" galvanized steel pipe 4' in length in the ground and then inserted the aluminum pipe into it. This method allows me to pull the mast out of the ground for any servicing that is required. For now I inserted my old steel mast into the end of the aluminum pipe and I am only at 22' overall now but when I next work on it, I will swap out the top section for more SCH-40 pipe and will extend the length to 33'. My mast is on a hill above my house so I was already pretty high up without going the full 33' for siting purposes. So far I have had gusts up to 45mph and I think I can tolerate any amount of wind short of a tornado. I also took my Davis apart so I can properly site the temp/humidty sensor separate from the rain bucket by making a PVC "monster". My design allows the sensor section of the PVC monster to be raised to accommodate various snow depths. Pictures of my installation can be seen here: http://weather.gladstonefamily.net/site/C8122 Lew >Message: 5 >Date: Sun, 9 Sep 2007 18:23:16 -0400 >From: Tim >Subject: [wxqc] Pole for wind gauge revisited >To: wxqc at lists.gladstonefamily.net >Message-ID: <78667338-7C4C-4425-A31C-63A3ADB58D3D at mac.com> >Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed > >I was browsing through the thread from June "Pole for wind gauge" >which was very informative. One thing I have been trying to figure >out, I have a antenna pole stuck in the ground and mounted to the >side of the roof. What does anyone think is the best pole material >and maximum unguyed height for this type of installation? Guying >simply is not in option on the cramped property I'm using. > >Regards, Tim >CW8595 From lew at farmingtonweather.com Mon Sep 10 14:09:24 2007 From: lew at farmingtonweather.com (webmaster) Date: Mon, 10 Sep 2007 14:09:24 -0500 Subject: [wxqc] wxqc Digest, Vol 35, Issue 4 Message-ID: <20070910190927.80B1B1802A4@relay02.roch.ny.frontiernet.net> When searching for a way to mount my weather station and anemometer I did a fair amount of research on various kinds of masts, mostly used for antennae installations. Hy-Gain makes an antennae mast that can be extended to about 60 feet and they say it can be used up to 30' without guy wires. I evaluated the pipes and thicknesses of them and determined that I could make an even stronger mast using SCH-40 aluminum pipe. I have double the wall thickness and a larger diameter. A local scrap dealer sells the pipe at scrap price so the pipes were pretty cheap relative to buying a mast like the Hy-gain model. I cemented a 2.5" galvanized steel pipe 4' in length in the ground and then inserted the aluminum pipe into it. This method allows me to pull the mast out of the ground for any servicing that is required. For now I inserted my old steel mast into the end of the aluminum pipe and I am only at 22' overall now but when I next work on it, I will swap out the top section for more SCH-40 pipe and will extend the length to 33'. My mast is on a hill above my house so I was already pretty high up without going the full 33' for siting purposes. So far I have had gusts up to 45mph and I think I can tolerate any amount of wind short of a tornado. I also took my Davis apart so I can properly site the temp/humidty sensor separate from the rain bucket by making a PVC "monster". My design allows the sensor section of the PVC monster to be raised to accommodate various snow depths. Pictures of my installation can be seen here: http://weather.gladstonefamily.net/site/C8122 Lew >Message: 5 >Date: Sun, 9 Sep 2007 18:23:16 -0400 >From: Tim >Subject: [wxqc] Pole for wind gauge revisited >To: wxqc at lists.gladstonefamily.net >Message-ID: <78667338-7C4C-4425-A31C-63A3ADB58D3D at mac.com> >Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed > >I was browsing through the thread from June "Pole for wind gauge" >which was very informative. One thing I have been trying to figure >out, I have a antenna pole stuck in the ground and mounted to the >side of the roof. What does anyone think is the best pole material >and maximum unguyed height for this type of installation? Guying >simply is not in option on the cramped property I'm using. > >Regards, Tim >CW8595 From m47 at mac.com Mon Sep 10 15:31:34 2007 From: m47 at mac.com (Tim) Date: Mon, 10 Sep 2007 16:31:34 -0400 Subject: [wxqc] PVC monster (was Re: Pole for wind gauge revisited) In-Reply-To: <20070910190934.D819418019C@relay02.roch.ny.frontiernet.net> References: <20070910190934.D819418019C@relay02.roch.ny.frontiernet.net> Message-ID: <1CE07F05-E2FB-460F-8239-A1789C7EAF3F@mac.com> I've seen you're PVC "monster" before and love the design. I don't have snow here but would be nice to raise the ISS when watering the lawn. My anemometer would not be freestanding (affixed at 8ft to the side of the roof), so perhaps I wouldn't need the concrete. Tim C8595 On Sep 10, 2007, at 3:08 PM, webmaster wrote: > When searching for a way to mount my weather station and anemometer I > did a fair amount of research on various kinds of masts, mostly used > for antennae installations. Hy-Gain makes an antennae mast that can > be extended to about 60 feet and they say it can be used up to 30' > without guy wires. I evaluated the pipes and thicknesses of them and > determined that I could make an even stronger mast using SCH-40 > aluminum pipe. I have double the wall thickness and a larger > diameter. A local scrap dealer sells the pipe at scrap price so the > pipes were pretty cheap relative to buying a mast like the Hy-gain > model. I cemented a 2.5" galvanized steel pipe 4' in length in the > ground and then inserted the aluminum pipe into it. This method > allows me to pull the mast out of the ground for any servicing that > is required. For now I inserted my old steel mast into the end of > the aluminum pipe and I am only at 22' overall now but when I next > work on it, I will swap out the top section for more SCH-40 pipe and > will extend the length to 33'. My mast is on a hill above my house > so I was already pretty high up without going the full 33' for > siting purposes. > > So far I have had gusts up to 45mph and I think I can tolerate any > amount of wind short of a tornado. > > I also took my Davis apart so I can properly site the temp/humidty > sensor separate from the rain bucket by making a PVC "monster". My > design allows the sensor section of the PVC monster to be raised to > accommodate various snow depths. > > Pictures of my installation can be seen here: > > http://weather.gladstonefamily.net/site/C8122 > > Lew > >> Message: 5 >> Date: Sun, 9 Sep 2007 18:23:16 -0400 >> From: Tim >> Subject: [wxqc] Pole for wind gauge revisited >> To: wxqc at lists.gladstonefamily.net >> Message-ID: <78667338-7C4C-4425-A31C-63A3ADB58D3D at mac.com> >> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed >> >> I was browsing through the thread from June "Pole for wind gauge" >> which was very informative. One thing I have been trying to figure >> out, I have a antenna pole stuck in the ground and mounted to the >> side of the roof. What does anyone think is the best pole material >> and maximum unguyed height for this type of installation? Guying >> simply is not in option on the cramped property I'm using. >> >> Regards, Tim >> CW8595 > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From brillig at gmail.com Mon Sep 10 15:20:25 2007 From: brillig at gmail.com (Victor Engel) Date: Mon, 10 Sep 2007 15:20:25 -0500 Subject: [wxqc] wxqc Digest, Vol 35, Issue 4 In-Reply-To: <20070910190934.D819418019C@relay02.roch.ny.frontiernet.net> References: <20070910190934.D819418019C@relay02.roch.ny.frontiernet.net> Message-ID: I looked only at your first picture, which is of the rain gauge. As pictured, it looks like it would be likely for rain to splash from the top of the PVC into the rain bucket, thus making the measurement too high. Victor On 9/10/07, webmaster wrote: > When searching for a way to mount my weather station and anemometer I > did a fair amount of research on various kinds of masts, mostly used > for antennae installations. Hy-Gain makes an antennae mast that can > be extended to about 60 feet and they say it can be used up to 30' > without guy wires. I evaluated the pipes and thicknesses of them and > determined that I could make an even stronger mast using SCH-40 > aluminum pipe. I have double the wall thickness and a larger > diameter. A local scrap dealer sells the pipe at scrap price so the > pipes were pretty cheap relative to buying a mast like the Hy-gain > model. I cemented a 2.5" galvanized steel pipe 4' in length in the > ground and then inserted the aluminum pipe into it. This method > allows me to pull the mast out of the ground for any servicing that > is required. For now I inserted my old steel mast into the end of > the aluminum pipe and I am only at 22' overall now but when I next > work on it, I will swap out the top section for more SCH-40 pipe and > will extend the length to 33'. My mast is on a hill above my house > so I was already pretty high up without going the full 33' for siting purposes. > > So far I have had gusts up to 45mph and I think I can tolerate any > amount of wind short of a tornado. > > I also took my Davis apart so I can properly site the temp/humidty > sensor separate from the rain bucket by making a PVC "monster". My > design allows the sensor section of the PVC monster to be raised to > accommodate various snow depths. > > Pictures of my installation can be seen here: > > http://weather.gladstonefamily.net/site/C8122 > > Lew > > >Message: 5 > >Date: Sun, 9 Sep 2007 18:23:16 -0400 > >From: Tim > >Subject: [wxqc] Pole for wind gauge revisited > >To: wxqc at lists.gladstonefamily.net > >Message-ID: <78667338-7C4C-4425-A31C-63A3ADB58D3D at mac.com> > >Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed > > > >I was browsing through the thread from June "Pole for wind gauge" > >which was very informative. One thing I have been trying to figure > >out, I have a antenna pole stuck in the ground and mounted to the > >side of the roof. What does anyone think is the best pole material > >and maximum unguyed height for this type of installation? Guying > >simply is not in option on the cramped property I'm using. > > > >Regards, Tim > >CW8595 > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From sullivan238 at cox.net Mon Sep 10 23:23:28 2007 From: sullivan238 at cox.net (Jim Sullivan) Date: Mon, 10 Sep 2007 21:23:28 -0700 Subject: [wxqc] Pole for wind gauge revisited In-Reply-To: <000901c7f35e$c70c83b0$55258b10$@net> Message-ID: Perhaps everybody knows this already, EMC conduit is meant to be bent. Sizes 1/2 to 1 inch bend with moderate force. Above 1 inch, conduit has good enough strength as a light-duty mast. Heavy wall conduit called IMC or Rigid is much heavier and isn't bent easily, but overkill for this use. I use 1-1/4 EMC for tripod mounted masts. Conduit only comes in 10 foot lengths and the sizes don't telescope into each other very well. If the joint is below the last mounting point, it may be ok to join them with a coupler. The coupler was never meant for this work, I don't recommend it. Use a steel coupler, not a cast zinc. Drill through the set-screw holes so the screws lock the pipe into the coupler, don't rely on friction. Above 10 feet I'd use a real antenna mast. Jim Sullivan -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Jim Sent: Sunday, September 09, 2007 20:58 To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Pole for wind gauge revisited Tim I use galvanized Electrical conduit instead of "antenna" pole. The wall thickness is a little thicker and the price is about the same. I have used a 10' section with a chimney mount which puts the anemometer between 5-6 ft. above the peek of the roof, and it has withstood 40-45 mph winds. You can see pictures on my QC report. If you don't have a chimney I would suggest mounting with the pole in the ground (maybe in a chunk of concrete for a anchor) so that it comes up at the peek and secure the pole with a "U" bracket to the eve of the roof at the peek. There are couplers available to connect pieces of conduit together so you can get the correct height. The instructions that came with my anemometer suggested 3 feet above the peek of the roof I tried to double that. Something to be aware of is metal poles have an effect on the magnets of the anemometer so you may also want to adapt the top to a 1 foot piece of PVC pipe (I used a 1" X 1' PVC nipple) to mount the anemometer on. All materials are available at home depot, Lowes, etc. Jim CW4367 -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Tim Sent: Sunday, September 09, 2007 3:23 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Pole for wind gauge revisited I was browsing through the thread from June "Pole for wind gauge" which was very informative. One thing I have been trying to figure out, I have a antenna pole stuck in the ground and mounted to the side of the roof. What does anyone think is the best pole material and maximum unguyed height for this type of installation? Guying simply is not in option on the cramped property I'm using. Regards, Tim CW8595 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From gerry.creager at tamu.edu Tue Sep 11 06:58:21 2007 From: gerry.creager at tamu.edu (Gerry Creager) Date: Tue, 11 Sep 2007 06:58:21 -0500 Subject: [wxqc] Pole for wind gauge revisited In-Reply-To: References: Message-ID: <46E682DD.6070606@tamu.edu> Not sure, but I think you meant "EMT" conduit in your discussion below. Rigid conduit approaches pipe in its rigidity but has a little less mass. It is threaded rather than butt-joint connected. I've used it for simple installations for antennas over the years, with appropriate guying, to heights of 50 feet with no problem save how to pivot it up safely. Both EMT and antenna mast are less structurally rigid and pose problems. The commercially available antenna mast material is a rolled steel thin-wall tube with telescoping joints that I've seen fail often. I prefer to use that stuff for short (16 ft or less) installations of rather light-weight, low wind-load devices (which we are discussing here). I don't recommend EMT conduit for any mast installations. gerry Jim Sullivan wrote: > Perhaps everybody knows this already, EMC conduit is meant to be bent. Sizes > 1/2 to 1 inch bend with moderate force. Above 1 inch, conduit has good > enough strength as a light-duty mast. Heavy wall conduit called IMC or Rigid > is much heavier and isn't bent easily, but overkill for this use. I use > 1-1/4 EMC for tripod mounted masts. > Conduit only comes in 10 foot lengths and the sizes don't telescope into > each other very well. If the joint is below the last mounting point, it may > be ok to join them with a coupler. The coupler was never meant for this > work, I don't recommend it. Use a steel coupler, not a cast zinc. Drill > through the set-screw holes so the screws lock the pipe into the coupler, > don't rely on friction. > Above 10 feet I'd use a real antenna mast. > > Jim Sullivan > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Jim > Sent: Sunday, September 09, 2007 20:58 > To: 'Discussion of weather data quality issues' > Subject: Re: [wxqc] Pole for wind gauge revisited > > > Tim > I use galvanized Electrical conduit instead of "antenna" pole. The wall > thickness is a little thicker and the price is about the same. I have used > a 10' section with a chimney mount which puts the anemometer between 5-6 ft. > above the peek of the roof, and it has withstood 40-45 mph winds. You can > see pictures on my QC report. If you don't have a chimney I would suggest > mounting with the pole in the ground (maybe in a chunk of concrete for a > anchor) so that it comes up at the peek and secure the pole with a "U" > bracket to the eve of the roof at the peek. There are couplers available to > connect pieces of conduit together so you can get the correct height. The > instructions that came with my anemometer suggested 3 feet above the peek of > the roof I tried to double that. Something to be aware of is metal poles > have an effect on the magnets of the anemometer so you may also want to > adapt the top to a 1 foot piece of PVC pipe (I used a 1" X 1' PVC nipple) to > mount the anemometer on. All materials are available at home depot, Lowes, > etc. > Jim > CW4367 > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Tim > Sent: Sunday, September 09, 2007 3:23 PM > To: wxqc at lists.gladstonefamily.net > Subject: [wxqc] Pole for wind gauge revisited > > I was browsing through the thread from June "Pole for wind gauge" > which was very informative. One thing I have been trying to figure > out, I have a antenna pole stuck in the ground and mounted to the > side of the roof. What does anyone think is the best pole material > and maximum unguyed height for this type of installation? Guying > simply is not in option on the cramped property I'm using. > > Regards, Tim > CW8595 > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -- Gerry Creager -- gerry.creager at tamu.edu Texas Mesonet -- AATLT, Texas A&M University Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983 Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843 From jimwc at frontiernet.net Tue Sep 11 10:03:29 2007 From: jimwc at frontiernet.net (Jim) Date: Tue, 11 Sep 2007 08:03:29 -0700 Subject: [wxqc] Pole for wind gauge revisited In-Reply-To: References: <000901c7f35e$c70c83b0$55258b10$@net> Message-ID: <000201c7f484$e9cff950$bd6febf0$@net> Jim & Tim I am using the EMC conduit but it is only a single 10 ft length. I agree with your comment about the coupler. I was mentioning this so that Tim would not try to mount a 10ft length of conduit at the bottom of the length with a single "U" clamp, and he would have a length of pipe below the "U" clamp and anchored to the ground. If he mounts at the peek of the house he would only need 4-6 ft above the peek un-supported. Jim CW4367 -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Jim Sullivan Sent: Monday, September 10, 2007 9:23 PM To: Discussion of weather data quality issues Subject: Re: [wxqc] Pole for wind gauge revisited Perhaps everybody knows this already, EMC conduit is meant to be bent. Sizes 1/2 to 1 inch bend with moderate force. Above 1 inch, conduit has good enough strength as a light-duty mast. Heavy wall conduit called IMC or Rigid is much heavier and isn't bent easily, but overkill for this use. I use 1-1/4 EMC for tripod mounted masts. Conduit only comes in 10 foot lengths and the sizes don't telescope into each other very well. If the joint is below the last mounting point, it may be ok to join them with a coupler. The coupler was never meant for this work, I don't recommend it. Use a steel coupler, not a cast zinc. Drill through the set-screw holes so the screws lock the pipe into the coupler, don't rely on friction. Above 10 feet I'd use a real antenna mast. Jim Sullivan -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Jim Sent: Sunday, September 09, 2007 20:58 To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Pole for wind gauge revisited Tim I use galvanized Electrical conduit instead of "antenna" pole. The wall thickness is a little thicker and the price is about the same. I have used a 10' section with a chimney mount which puts the anemometer between 5-6 ft. above the peek of the roof, and it has withstood 40-45 mph winds. You can see pictures on my QC report. If you don't have a chimney I would suggest mounting with the pole in the ground (maybe in a chunk of concrete for a anchor) so that it comes up at the peek and secure the pole with a "U" bracket to the eve of the roof at the peek. There are couplers available to connect pieces of conduit together so you can get the correct height. The instructions that came with my anemometer suggested 3 feet above the peek of the roof I tried to double that. Something to be aware of is metal poles have an effect on the magnets of the anemometer so you may also want to adapt the top to a 1 foot piece of PVC pipe (I used a 1" X 1' PVC nipple) to mount the anemometer on. All materials are available at home depot, Lowes, etc. Jim CW4367 -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Tim Sent: Sunday, September 09, 2007 3:23 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Pole for wind gauge revisited I was browsing through the thread from June "Pole for wind gauge" which was very informative. One thing I have been trying to figure out, I have a antenna pole stuck in the ground and mounted to the side of the roof. What does anyone think is the best pole material and maximum unguyed height for this type of installation? Guying simply is not in option on the cramped property I'm using. Regards, Tim CW8595 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From webmaster at farmingtonweather.com Tue Sep 11 10:12:17 2007 From: webmaster at farmingtonweather.com (webmaster) Date: Tue, 11 Sep 2007 10:12:17 -0500 Subject: [wxqc] wxqc Digest, Vol 35, Issue 5 In-Reply-To: References: Message-ID: <20070911151218.CCF741800EB@relay02.roch.ny.frontiernet.net> It if was me, I would simply put a bucket/coffee can over the rain bucket when watering the yard. Simple solution for a simple problem. I haven't watered my yard since installing the Davis but that is what I will do. At 12:43 AM 9/11/2007, you wrote: >Date: Mon, 10 Sep 2007 16:31:34 -0400 >From: Tim >Subject: Re: [wxqc] PVC monster (was Re: Pole for wind gauge > revisited) > >I've seen you're PVC "monster" before and love the design. I don't >have snow here but would be nice to raise the ISS when watering the >lawn. My anemometer would not be freestanding (affixed at 8ft to the >side of the roof), so perhaps I wouldn't need the concrete. > >Tim >C8595 From webmaster at farmingtonweather.com Tue Sep 11 10:22:11 2007 From: webmaster at farmingtonweather.com (webmaster) Date: Tue, 11 Sep 2007 10:22:11 -0500 Subject: [wxqc] wxqc Digest, Vol 35, Issue 5 In-Reply-To: References: Message-ID: <20070911152212.80884B43CC@relay01.roch.ny.frontiernet.net> Victor, I assume you mean the smaller vertical pipe that the rain bucket is mounted on? I could make the top of it pointed if I thought I was getting much splash. I could also cut the pipe shorter so that the top of the pipe was lower. For comparison purposes, do you have the "shelf" that Davis sells for mounting the solar and UV sensor? The shelf and the sensors themselves are closer to the top of the bucket and have much more surface area than small PVC pipe I have sticking up. If Davis doesn't think having 10-12 sq inches of flat surface right below the edge of the bucket then the 3 sq inches of flat surface I have much lower down the side couldn't be an issue. The closest weather station to me is a Davis mounted 1 foot above the roof of the house next to his chimney. Not only is that a bad location for temp readings, but how much splash do you think he is getting off of the roof of the house? Since I assume 99% of the people have their rain bucket mounted above the temp sensor that means their rain bucket is not sited properly, i.e. the bucket is not 2' above the ground causing a bad reading. Likewise, if they have the anemometer mounted on the back side of the rain bucket, then the arm of the anemometer can also cause some splash. Thanks for the feedback, but I think it is inconsequential compared to how most people have theirs mounted :) Lew At 12:43 AM 9/11/2007, you wrote: >Date: Mon, 10 Sep 2007 15:20:25 -0500 >From: "Victor Engel" >Subject: Re: [wxqc] wxqc Digest, Vol 35, Issue 4 >To: "Discussion of weather data quality issues" > >Message-ID: > >Content-Type: text/plain; charset=ISO-8859-1 > >I looked only at your first picture, which is of the rain gauge. As >pictured, it looks like it would be likely for rain to splash from the >top of the PVC into the rain bucket, thus making the measurement too >high. > >Victor From m47 at mac.com Tue Sep 11 10:27:42 2007 From: m47 at mac.com (Tim) Date: Tue, 11 Sep 2007 11:27:42 -0400 Subject: [wxqc] wxqc Digest, Vol 35, Issue 5 In-Reply-To: <20070911151218.CCF741800EB@relay02.roch.ny.frontiernet.net> References: <20070911151218.CCF741800EB@relay02.roch.ny.frontiernet.net> Message-ID: <2DDBA9CD-BE4E-4119-B8BC-103ADAD6F23C@mac.com> Simple solution for the rain gauge, but not for the thermometer/ hygrometer, which I assume would get thrown off if constantly doused with water. On Sep 11, 2007, at 11:12 AM, webmaster wrote: > It if was me, I would simply put a bucket/coffee can over the rain > bucket when watering the yard. Simple solution for a simple > problem. I haven't watered my yard since installing the Davis but > that is what I will do. > > At 12:43 AM 9/11/2007, you wrote: >> Date: Mon, 10 Sep 2007 16:31:34 -0400 >> From: Tim >> Subject: Re: [wxqc] PVC monster (was Re: Pole for wind gauge >> revisited) >> >> I've seen you're PVC "monster" before and love the design. I don't >> have snow here but would be nice to raise the ISS when watering the >> lawn. My anemometer would not be freestanding (affixed at 8ft to the >> side of the roof), so perhaps I wouldn't need the concrete. >> >> Tim >> C8595 > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From brillig at gmail.com Thu Sep 13 18:29:40 2007 From: brillig at gmail.com (Victor Engel) Date: Thu, 13 Sep 2007 18:29:40 -0500 Subject: [wxqc] Rain included in analysis? Message-ID: I'm assuming rain is not included in the analysis graphs on gladstonefamily.net. Correct? I base this presumption on my last error report, which I follow to this link: http://tinyurl.com/yt6s7n I've also added Austin Bergstrom, Camp Mabry, and the station closest to mine. At the point where the closest station and mine dip way below the others, there was a very strong rainstorm that dumped about 1/3 inch of rain in 10-15 minutes at my location and a similar amount at the nearby location. This rain was localized, though, and other stations around the area got little or no rain. I think wind, barometer, rain, and temperature data all confirm each other and could indicate the temperature is not off. But since other stations didn't get the rainfall, maybe it was ignored in the analysis. Or maybe rain is not used at all in the analysis. Comments? Victor Engel CW6155 From gary.oldham at adelphia.net Thu Sep 13 19:10:43 2007 From: gary.oldham at adelphia.net (=?utf-8?B?R2FyeSBPbGRoYW0=?=) Date: Fri, 14 Sep 2007 00:10:43 +0000 Subject: [wxqc] Rain included in analysis? In-Reply-To: References: Message-ID: <499736449-1189728647-cardhu_decombobulator_blackberry.rim.net-579156395-@bxe103.bisx.prod.on.blackberry> I'm pretty sure rain is NOT included in any of that data analysis. As you mention, rain events are often highly localized and station-to-station comparison on that basis alone would be of questionable value. Further compunding this is the fact that many popular personal weather stations, notably the Oregon Scientific, LaCrosse, and the very pricey Weather Hawk lines, only record/report in coarse 0.04" increments, further invalidating comparisons with stations reporting at more granular 0.01" increments. Gary CW0146 Sent from my BlackBerry? wireless device -----Original Message----- From: "Victor Engel" Date: Thu, 13 Sep 2007 18:29:40 To:"Discussion of weather data quality issues" Subject: [wxqc] Rain included in analysis? I'm assuming rain is not included in the analysis graphs on gladstonefamily.net. Correct? I base this presumption on my last error report, which I follow to this link: http://tinyurl.com/yt6s7n I've also added Austin Bergstrom, Camp Mabry, and the station closest to mine. At the point where the closest station and mine dip way below the others, there was a very strong rainstorm that dumped about 1/3 inch of rain in 10-15 minutes at my location and a similar amount at the nearby location. This rain was localized, though, and other stations around the area got little or no rain. I think wind, barometer, rain, and temperature data all confirm each other and could indicate the temperature is not off. But since other stations didn't get the rainfall, maybe it was ignored in the analysis. Or maybe rain is not used at all in the analysis. Comments? Victor Engel CW6155 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From webmaster at farmingtonweather.com Thu Sep 13 20:27:28 2007 From: webmaster at farmingtonweather.com (webmaster) Date: Thu, 13 Sep 2007 20:27:28 -0500 Subject: [wxqc] wxqc Digest, Vol 35, Issue 6 In-Reply-To: References: Message-ID: <20070914012724.E5F44B41CB@relay01.roch.ny.frontiernet.net> Hmm....do you see the humidity or temp guage go wacky when it rains? The temp and humidity sensors must be built to withstand rain without affecting their readings? I wouldn't put one of those oscillating sprinklers under the temp sensor that in it's arc would be shooting water up into it from below, but from all other angles the temp and humid sensor is presumably meant to get wet. Lew At 07:11 PM 9/13/2007, you wrote: >Simple solution for the rain gauge, but not for the thermometer/ >hygrometer, which I assume would get thrown off if constantly doused >with water. From m47 at mac.com Thu Sep 13 20:35:57 2007 From: m47 at mac.com (Tim) Date: Thu, 13 Sep 2007 21:35:57 -0400 Subject: [wxqc] wxqc Digest, Vol 35, Issue 6 In-Reply-To: <20070914012724.E5F44B41CB@relay01.roch.ny.frontiernet.net> References: <20070914012724.E5F44B41CB@relay01.roch.ny.frontiernet.net> Message-ID: <9E0BA3BA-4A1E-47F2-BD29-279D818EBD73@mac.com> I had a bad experience with a cheaper weather station that, in fact, did just that. It got really wacky. Presumably moisture got inside the sensor as the humidity reading went sky high for some time. You're right about the davis though, it seems to do just fine. On Sep 13, 2007, at 9:27 PM, webmaster wrote: > Hmm....do you see the humidity or temp guage go wacky when it > rains? The temp and humidity sensors must be built to withstand > rain without affecting their readings? > > I wouldn't put one of those oscillating sprinklers under the temp > sensor that in it's arc would be shooting water up into it from > below, but from all other angles the temp and humid sensor is > presumably meant to get wet. > > Lew > > At 07:11 PM 9/13/2007, you wrote: >> Simple solution for the rain gauge, but not for the thermometer/ >> hygrometer, which I assume would get thrown off if constantly doused >> with water. > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From brillig at gmail.com Thu Sep 13 21:32:15 2007 From: brillig at gmail.com (Victor Engel) Date: Thu, 13 Sep 2007 21:32:15 -0500 Subject: [wxqc] wxqc Digest, Vol 35, Issue 6 In-Reply-To: <9E0BA3BA-4A1E-47F2-BD29-279D818EBD73@mac.com> References: <20070914012724.E5F44B41CB@relay01.roch.ny.frontiernet.net> <9E0BA3BA-4A1E-47F2-BD29-279D818EBD73@mac.com> Message-ID: My neighbor's weather station has been doing that. http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KTXAUSTI4 At first it was the windspeed shooting up over 100mph every time it rained. Now is wind direction and temperature are essentially stuck. I'm not sure what happened to the dewpoint. Perhaps his humidity meter is disconnected. The only thing that really works is the barometer (which needs calibration) and the windspeed. I wish he'd just take the thing offline, because he's so close to me that in the map view, his icon covers mine unless you zoom in really close. Changing the subject, I noticed on the quality summary page that there are some new options on the map now. I presume the one with the date shows that date's weather for the location. That's pretty cool. On 9/13/07, Tim wrote: > I had a bad experience with a cheaper weather station that, in fact, > did just that. It got really wacky. Presumably moisture got inside > the sensor as the humidity reading went sky high for some time. > You're right about the davis though, it seems to do just fine. > > On Sep 13, 2007, at 9:27 PM, webmaster wrote: > > > Hmm....do you see the humidity or temp guage go wacky when it > > rains? The temp and humidity sensors must be built to withstand > > rain without affecting their readings? > > > > I wouldn't put one of those oscillating sprinklers under the temp > > sensor that in it's arc would be shooting water up into it from > > below, but from all other angles the temp and humid sensor is > > presumably meant to get wet. > > > > Lew > > > > At 07:11 PM 9/13/2007, you wrote: > >> Simple solution for the rain gauge, but not for the thermometer/ > >> hygrometer, which I assume would get thrown off if constantly doused > >> with water. > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From nmupdraft at gmail.com Thu Sep 13 21:14:20 2007 From: nmupdraft at gmail.com (jody radzik) Date: Thu, 13 Sep 2007 20:14:20 -0600 Subject: [wxqc] Frequency of barometer adjustment Message-ID: Hello all. I've got a Davis Vantage Pro2 reporting to the mesonet as CW6266. I've found that I stay within quality control parameters if my pressure reading is between that reported by KLAM (Los Alamos) and KSAF (Santa Fe). I'm in Tesuque, which is between the two yet closer to Santa Fe. My reading will stay on the money for various amounts of time, but invariably it will suddenly swing high or low, and stay high or low rather than coming back into line. I find myself making adjustments about 4-5 times a month. Is this normal, or should I be worrying about the performance of my pressure sensor? Thanks in advance for the help. --jody radzik +nmupdraft.org From steve at softwx.com Fri Sep 14 09:28:45 2007 From: steve at softwx.com (Steve Hatchett) Date: Fri, 14 Sep 2007 08:28:45 -0600 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: References: Message-ID: <000001c7f6db$90eed370$b2cc7a50$@com> Which software program are you using to send data to APRS/CWOP? If it is sending the pressure value just as it comes from the console, then that is very likely your problem. The console provides the sea level pressure. The values CWOP wants, and the value often reported by the airport stations is altimeter. The software program should convert from sea level pressure to altimeter before sending to APRS/CWOP. There are several programs that do this including: WeatherLink (latest version), WeatherDisplay, PCWeatherStation, VPLive. There may be others as well. If you are above around 1000 feet, you will definitely see your CWOP pressure drift as the seasons change, relative to nearby stations. This is because sea level pressure includes temperature in its calculation, while altimeter doesn't. It looks like you are using WeatherTracker. I remember trading some emails with the author in which I provided him some information and algorithms on the topic. I'm not sure if he's had time to incorporate them. Check with the him. If it turns out that WeatherTracker is sending altimeter, then post another message. Normally you should not need to calibrate your pressure sensor very often - maybe once every year or two, and even then the adjustment would likely be small. Steve SoftWx -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of jody radzik Sent: 09/13/2007 8:14 PM To: Discussion of weather data quality issues Subject: [wxqc] Frequency of barometer adjustment Hello all. I've got a Davis Vantage Pro2 reporting to the mesonet as CW6266. I've found that I stay within quality control parameters if my pressure reading is between that reported by KLAM (Los Alamos) and KSAF (Santa Fe). I'm in Tesuque, which is between the two yet closer to Santa Fe. My reading will stay on the money for various amounts of time, but invariably it will suddenly swing high or low, and stay high or low rather than coming back into line. I find myself making adjustments about 4-5 times a month. Is this normal, or should I be worrying about the performance of my pressure sensor? Thanks in advance for the help. --jody radzik +nmupdraft.org _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From nmupdraft at gmail.com Tue Sep 18 21:28:30 2007 From: nmupdraft at gmail.com (jody radzik) Date: Tue, 18 Sep 2007 20:28:30 -0600 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: <000001c7f6db$90eed370$b2cc7a50$@com> References: <000001c7f6db$90eed370$b2cc7a50$@com> Message-ID: See attached GIF file. This is the pattern. I will hold with MADIS for a while, and then suddenly I'll shoot up higher that what MADIS says I should be at. This happens during calm weather as much as windy. On 9/14/07, Steve Hatchett wrote: > Which software program are you using to send data to APRS/CWOP? If it is > sending the pressure value just as it comes from the console, then that is > very likely your problem. The console provides the sea level pressure. The > values CWOP wants, and the value often reported by the airport stations is > altimeter. The software program should convert from sea level pressure to > altimeter before sending to APRS/CWOP. There are several programs that do > this including: WeatherLink (latest version), WeatherDisplay, > PCWeatherStation, VPLive. There may be others as well. If you are above > around 1000 feet, you will definitely see your CWOP pressure drift as the > seasons change, relative to nearby stations. This is because sea level > pressure includes temperature in its calculation, while altimeter doesn't. > > It looks like you are using WeatherTracker. I remember trading some emails > with the author in which I provided him some information and algorithms on > the topic. I'm not sure if he's had time to incorporate them. Check with the > him. > > If it turns out that WeatherTracker is sending altimeter, then post another > message. Normally you should not need to calibrate your pressure sensor very > often - maybe once every year or two, and even then the adjustment would > likely be small. > > Steve > SoftWx > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of jody radzik > Sent: 09/13/2007 8:14 PM > To: Discussion of weather data quality issues > Subject: [wxqc] Frequency of barometer adjustment > > Hello all. > > I've got a Davis Vantage Pro2 reporting to the mesonet as CW6266. > I've found that I stay within quality control parameters if my > pressure reading is between that reported by KLAM (Los Alamos) and > KSAF (Santa Fe). I'm in Tesuque, which is between the two yet closer > to Santa Fe. > > My reading will stay on the money for various amounts of time, but > invariably it will suddenly swing high or low, and stay high or low > rather than coming back into line. I find myself making adjustments > about 4-5 times a month. Is this normal, or should I be worrying > about the performance of my pressure sensor? > > Thanks in advance for the help. > > --jody radzik > +nmupdraft.org > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > -------------- next part -------------- A non-text attachment was scrubbed... Name: C6266.gif Type: image/gif Size: 6390 bytes Desc: not available Url : http://server.gladstonefamily.net/pipermail/wxqc/attachments/20070918/3fd458da/attachment-0001.gif From kdmiller at oldsgmail.com Tue Sep 18 21:49:50 2007 From: kdmiller at oldsgmail.com (Keith Miller) Date: Tue, 18 Sep 2007 22:49:50 -0400 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: Message-ID: > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of > jody radzik > Sent: Tuesday, September 18, 2007 10:29 PM > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Frequency of barometer adjustment > > > See attached GIF file. This is the pattern. I will hold with MADIS > for a while, and then suddenly I'll shoot up higher that what MADIS > says I should be at. This happens during calm weather as much as > windy. > You're at 6800' and as Steve explained, you're seeing the difference between altimeter vs sea level reduced pressure. The later varies with temperature, MADIS expects altimeter pressure and applies it's own temperature adjustment. I've seen this at only 500' and the higher your are the worse it is. If your software can't calculate altimeter pressure, set your console (or envoy) altitude to zero and apply an offset. Keith -- CW5250 => http://weather.stadhaugh.com From radiotech at bellsouth.net Wed Sep 19 05:00:16 2007 From: radiotech at bellsouth.net (Alan Alsobrook) Date: Wed, 19 Sep 2007 06:00:16 -0400 Subject: [wxqc] AS245- Rain fall Failure. Message-ID: <46F0F330.1080406@bellsouth.net> Wouldn't you know it, right in the middle of the best rain event in the past year my rain gauge decided to take a dump so to speak. Right at 0000 9/19 EDT the rain gauge quit sending data. I have restored it at 0600 local, in the mean time it lost an estimated .50 to .75" of rain. Not sure why it quite, still trying to figure that one out, I did replace both batteries and reset it without any luck. It wasn't until I removed it to the work bench and pull it all apart and put it back together that it started working. No obvious problems were found. I'm guessing that it may have been dead batteries, and that since I changed them one at a time it may have been in a locked up state, so it wasn't until I removed both batteries at the same time that it started working again. We haven't seen the sun to recharge to solar batteries in a few days, and the alkalines were old. Side note AS229 is still off-line until I have time to restore an internet connection to its site. (Project is in progress) -- Alan Alsobrook AS-245 (KDQOF-1) St. Augustine Fl. 32086 904-829-8885 aalso at Bellsouth.net From steve at softwx.com Wed Sep 19 09:47:13 2007 From: steve at softwx.com (Steve Hatchett) Date: Wed, 19 Sep 2007 08:47:13 -0600 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: References: <000001c7f6db$90eed370$b2cc7a50$@com> Message-ID: <003701c7facb$f90073d0$eb015b70$@com> The pressure drop in the graph is absolutely related to the sea level pressure (SLP) calculation. The VP console contains a pressure sensor that produces a raw pressure value. The console uses a formula to convert that to SLP. This is the value you see on the console. The SLP formula uses temperature as one of the inputs. The way it uses it is to calculate a mean temperature between the current temperature and temperature at the top of the hour 12 hours in the past. Use the 12 hour mean temperature is done to remove some of the diurnal temperature swings. However, if you have a large temperature change in less than a hour period, you will see a visible jog in your VP pressure about 12 hours later when the formula changes from using one top of the hour temperature to the next (very different) temperature. If you look at your data 12 hours prior to the pressure anomaly in your graph, you will see just such a temperature change. You will not see those sorts of anomalies in altimeter values, because altimeter doesn't use temperature in its calculation. Also note that this temperature/pressure anomaly doesn't show up at all at sea level, and its effect is more noticeable the higher your altitude. That is why you see it so dramatically. These sorts of calculation/temperature pressure anomalies are not unique to the VP. If you get a cold front passing through with a very quick temperature drop, and then looked at the SLP (not altimeter) reported by a NWS station 12 hours later, you will likely see a matching effect on the reported pressure. It won't be as dramatic as with the VP, because the VP only uses the temperature at the top of the hour for the 12 hour past temperature, whereas the NWS formula probably uses the true 12 hour past temperature. The NWS may also have other things in their SLP formula to mitigate temperate induced anomalies. Another higher altitude VP user and I suggested to Davis that they modify their formula to lessen this hourly, chunky pressure anomaly. They did this, via a firmware upgrade earlier this year. Now, rather than using the temperature at the top of the hour for the 12 hour past temperature, they either use the true 12 hour ago temperature (even those between the hour), or they use an averaging formula to give a more representative value for the 12 hour temp. I'm not sure which way they chose to implement it, but either way is a great improvement for folks living at altitude. Steve SoftWx -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of jody radzik Sent: 09/18/2007 8:29 PM To: Discussion of weather data quality issues Subject: Re: [wxqc] Frequency of barometer adjustment See attached GIF file. This is the pattern. I will hold with MADIS for a while, and then suddenly I'll shoot up higher that what MADIS says I should be at. This happens during calm weather as much as windy. On 9/14/07, Steve Hatchett wrote: > Which software program are you using to send data to APRS/CWOP? If it > is sending the pressure value just as it comes from the console, then > that is very likely your problem. The console provides the sea level > pressure. The values CWOP wants, and the value often reported by the > airport stations is altimeter. The software program should convert > from sea level pressure to altimeter before sending to APRS/CWOP. > There are several programs that do this including: WeatherLink (latest > version), WeatherDisplay, PCWeatherStation, VPLive. There may be > others as well. If you are above around 1000 feet, you will definitely > see your CWOP pressure drift as the seasons change, relative to nearby > stations. This is because sea level pressure includes temperature in its calculation, while altimeter doesn't. > > It looks like you are using WeatherTracker. I remember trading some > emails with the author in which I provided him some information and > algorithms on the topic. I'm not sure if he's had time to incorporate > them. Check with the him. > > If it turns out that WeatherTracker is sending altimeter, then post > another message. Normally you should not need to calibrate your > pressure sensor very often - maybe once every year or two, and even > then the adjustment would likely be small. > > Steve > SoftWx > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of jody > radzik > Sent: 09/13/2007 8:14 PM > To: Discussion of weather data quality issues > Subject: [wxqc] Frequency of barometer adjustment > > Hello all. > > I've got a Davis Vantage Pro2 reporting to the mesonet as CW6266. > I've found that I stay within quality control parameters if my > pressure reading is between that reported by KLAM (Los Alamos) and > KSAF (Santa Fe). I'm in Tesuque, which is between the two yet closer > to Santa Fe. > > My reading will stay on the money for various amounts of time, but > invariably it will suddenly swing high or low, and stay high or low > rather than coming back into line. I find myself making adjustments > about 4-5 times a month. Is this normal, or should I be worrying > about the performance of my pressure sensor? > > Thanks in advance for the help. > > --jody radzik > +nmupdraft.org > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or > change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or > change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From radiotech at bellsouth.net Wed Sep 19 14:25:15 2007 From: radiotech at bellsouth.net (Alan Alsobrook) Date: Wed, 19 Sep 2007 15:25:15 -0400 Subject: [wxqc] AS245- Rain fall Failure. In-Reply-To: <46F0F330.1080406@bellsouth.net> References: <46F0F330.1080406@bellsouth.net> Message-ID: <46F1779B.9070404@bellsouth.net> Update, apparently it didn't remain working long. The Rain Gauge has now been replaced with a backup unit. Unfortunately at least another 1" was not measured. Alan Alsobrook wrote: > Wouldn't you know it, right in the middle of the best rain event in the > past year my rain gauge decided to take a dump so to speak. Right at > 0000 9/19 EDT the rain gauge quit sending data. I have restored it at > 0600 local, in the mean time it lost an estimated .50 to .75" of rain. -- Alan Alsobrook AS245 St. Augustine Fl. 32086 904-829-8885 aalso at Bellsouth.net From nmupdraft at gmail.com Wed Sep 19 15:42:29 2007 From: nmupdraft at gmail.com (jody radzik) Date: Wed, 19 Sep 2007 14:42:29 -0600 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: <003701c7facb$f90073d0$eb015b70$@com> References: <000001c7f6db$90eed370$b2cc7a50$@com> <003701c7facb$f90073d0$eb015b70$@com> Message-ID: Perhaps I should have explained this, but the pressure drop is due to my correcting the pressure reading to the MADIS QC by changing the offset. It's what happens before the drop that's the issue. I will stay with the QC reading for a few days to a week or so, and then my reading will suddenly go up relative to the MADIS. I'm thinking my pressure sensor just goes screwy every now and then, but I don't know enough about it, hence my putting it to the experts here. On 9/19/07, Steve Hatchett wrote: > The pressure drop in the graph is absolutely related to the sea level > pressure (SLP) calculation. The VP console contains a pressure sensor that > produces a raw pressure value. The console uses a formula to convert that to > SLP. This is the value you see on the console. The SLP formula uses > temperature as one of the inputs. The way it uses it is to calculate a mean > temperature between the current temperature and temperature at the top of > the hour 12 hours in the past. Use the 12 hour mean temperature is done to > remove some of the diurnal temperature swings. However, if you have a large > temperature change in less than a hour period, you will see a visible jog in > your VP pressure about 12 hours later when the formula changes from using > one top of the hour temperature to the next (very different) temperature. If > you look at your data 12 hours prior to the pressure anomaly in your graph, > you will see just such a temperature change. You will not see those sorts of > anomalies in altimeter values, because altimeter doesn't use temperature in > its calculation. Also note that this temperature/pressure anomaly doesn't > show up at all at sea level, and its effect is more noticeable the higher > your altitude. That is why you see it so dramatically. > > These sorts of calculation/temperature pressure anomalies are not unique to > the VP. If you get a cold front passing through with a very quick > temperature drop, and then looked at the SLP (not altimeter) reported by a > NWS station 12 hours later, you will likely see a matching effect on the > reported pressure. It won't be as dramatic as with the VP, because the VP > only uses the temperature at the top of the hour for the 12 hour past > temperature, whereas the NWS formula probably uses the true 12 hour past > temperature. The NWS may also have other things in their SLP formula to > mitigate temperate induced anomalies. > > Another higher altitude VP user and I suggested to Davis that they modify > their formula to lessen this hourly, chunky pressure anomaly. They did this, > via a firmware upgrade earlier this year. Now, rather than using the > temperature at the top of the hour for the 12 hour past temperature, they > either use the true 12 hour ago temperature (even those between the hour), > or they use an averaging formula to give a more representative value for the > 12 hour temp. I'm not sure which way they chose to implement it, but either > way is a great improvement for folks living at altitude. > > Steve > SoftWx > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of jody radzik > Sent: 09/18/2007 8:29 PM > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Frequency of barometer adjustment > > See attached GIF file. This is the pattern. I will hold with MADIS for a > while, and then suddenly I'll shoot up higher that what MADIS says I should > be at. This happens during calm weather as much as windy. > > On 9/14/07, Steve Hatchett wrote: > > Which software program are you using to send data to APRS/CWOP? If it > > is sending the pressure value just as it comes from the console, then > > that is very likely your problem. The console provides the sea level > > pressure. The values CWOP wants, and the value often reported by the > > airport stations is altimeter. The software program should convert > > from sea level pressure to altimeter before sending to APRS/CWOP. > > There are several programs that do this including: WeatherLink (latest > > version), WeatherDisplay, PCWeatherStation, VPLive. There may be > > others as well. If you are above around 1000 feet, you will definitely > > see your CWOP pressure drift as the seasons change, relative to nearby > > stations. This is because sea level pressure includes temperature in its > calculation, while altimeter doesn't. > > > > It looks like you are using WeatherTracker. I remember trading some > > emails with the author in which I provided him some information and > > algorithms on the topic. I'm not sure if he's had time to incorporate > > them. Check with the him. > > > > If it turns out that WeatherTracker is sending altimeter, then post > > another message. Normally you should not need to calibrate your > > pressure sensor very often - maybe once every year or two, and even > > then the adjustment would likely be small. > > > > Steve > > SoftWx > > > > -----Original Message----- > > From: wxqc-bounces at lists.gladstonefamily.net > > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of jody > > radzik > > Sent: 09/13/2007 8:14 PM > > To: Discussion of weather data quality issues > > Subject: [wxqc] Frequency of barometer adjustment > > > > Hello all. > > > > I've got a Davis Vantage Pro2 reporting to the mesonet as CW6266. > > I've found that I stay within quality control parameters if my > > pressure reading is between that reported by KLAM (Los Alamos) and > > KSAF (Santa Fe). I'm in Tesuque, which is between the two yet closer > > to Santa Fe. > > > > My reading will stay on the money for various amounts of time, but > > invariably it will suddenly swing high or low, and stay high or low > > rather than coming back into line. I find myself making adjustments > > about 4-5 times a month. Is this normal, or should I be worrying > > about the performance of my pressure sensor? > > > > Thanks in advance for the help. > > > > --jody radzik > > +nmupdraft.org > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or > > change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or > > change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From steve at softwx.com Wed Sep 19 22:53:09 2007 From: steve at softwx.com (Steve Hatchett) Date: Wed, 19 Sep 2007 21:53:09 -0600 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: References: <000001c7f6db$90eed370$b2cc7a50$@com> <003701c7facb$f90073d0$eb015b70$@com> Message-ID: <003b01c7fb39$c44b3800$4ce1a800$@com> The problem is that as long as you compare your SLP to nearby stations' altimeter, you will never track them. The reason is that you are comparing apples and oranges. SLP and altimeter simply aren't the same, and at your altitude the difference is significant. Using my handy dandy pressure calculator here is an example: Let's say your console is new, and has a calibration offset of 0. The humidity is 50%, and the mean temperature between now and 12 hours ago is 60 degrees F. Given those values, the raw pressure that the sensor in your console is producing (which you don't see, but it's used by the console to calculate the SLP you do see) is 806.13 mb. Given that raw pressure, the altimeter value for your station would calculate out to be 1038.18 mb (which is quite a bit different than the SLP). You look at your CWOP QC and you see your pressure is way under the nearby stations that are reporting altimeters of around 1038, so you calibrate your console to read 1038.18 mb. This sets a calibration offset value inside the console of +11.18 (1038.18-1027). Now your console matches the QC. You've forced the console to have its SLP "look like" an altimeter value. You're under a very static pressure pattern, and the altimeter values of the nearby stations remain totally static for a few days, stuck right on 1038.18 mb. But the average temperatures are getting hotter. A day or two later, the mean 12 hour temperature is now 75 degrees F. Note that the pressure generated by your console's perfectly functioning sensor is still 806.13 mb, because like the nearby stations, the pressure over your area has been totally static. You look at your console and your QC, and are surprised to see that the console now shows a pressure of 1030.61 mb. Damn! The console must be screwed up because it's drifted way off...almost 8 mb! No, the console's fine. The raw reading in the console is still 806.13 mb. But because of that 15 degree change in the mean temperature, the SLP now calculates out to 1019.43 mb. And you had calibrated in an offset of +11.18 mb a couple days before, so the console now is reading 1030.61 mb (1019.43 + 11.18). That's the problem. As long as you try to send SLP to CWOP and compare your results to the altimeter values the nearby stations are sending to CWOP, you will never track. You will forever be adjusting your pressure as you manually compensate for the effect the changes in temperature have on the SLP you're sending to CWOP. Two years ago I was exactly where you are now, and I too thought my console was screwed up until someone pointed out the SLP vs. altimeter issue. I was calibrating my console every couple weeks. At the time there were no programs that calculated altimeter and sent it to CWOP for VP stations, so I wrote one. Once I started sending true altimeter values, and backed out the fakey calibration I had imposed on the console, my pressure started tracking perfectly on my CWOP QC, and now I almost never need to calibrate my pressure. Steve SoftWx From kdmiller at oldsgmail.com Wed Sep 19 23:16:10 2007 From: kdmiller at oldsgmail.com (Keith Miller) Date: Thu, 20 Sep 2007 00:16:10 -0400 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: <003b01c7fb39$c44b3800$4ce1a800$@com> Message-ID: > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Steve > Hatchett > Sent: Wednesday, September 19, 2007 11:53 PM > To: 'Discussion of weather data quality issues' > Subject: Re: [wxqc] Frequency of barometer adjustment > > > Two years ago I was exactly where you are now, and I too thought > my console was screwed up until someone pointed out the SLP vs. > altimeter issue. I was calibrating my console every couple > weeks. At the time there were no programs that calculated > altimeter and sent it to CWOP for VP stations, so I wrote one. > Once I started sending true altimeter values, and backed out > the fakey calibration I had imposed on the console, my pressure > started tracking perfectly on my CWOP QC, and now I almost > never need to calibrate my pressure. > Steve didn't mention it, but he wrote a handy program to back track the VP SLP calculation to altimeter pressure: http://www.softwx.com/weather/vppressurecalc.html Your problem is a simple matter of you are trying to correct SLP pressure and you'll chase that forever, unless you take steps to report altimeter pressure. I started down that path, but soon realized it'd never work. Set altitude to zero and set an offset, I wish it had another decimal place, but I now stay well within 1mb of what MADIS expects: http://weather.gladstonefamily.net/site/C5250 Wow, just looked and 100% MADIS QC for all, usually the dew point doesn't cut it... Maybe because it's been so dry here the past month or so? Keith -- CW5250 => http://weather.stadhaugh.com From steve at softwx.com Thu Sep 20 03:12:19 2007 From: steve at softwx.com (Steve Hatchett) Date: Thu, 20 Sep 2007 02:12:19 -0600 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: References: <003b01c7fb39$c44b3800$4ce1a800$@com> Message-ID: <003d01c7fb5d$f89bf850$e9d3e8f0$@com> I just wanted to note that using the technique of setting the console elevation to 0 (which turns off the SLP calculation from occurring in the console) and then setting a fixed calibration offset to adjust for elevation, while better than reporting SLP, it is not quite the same as reporting true altimeter. At Keith's lower elevation (under 1000') the difference is probably between the zero elevation method and true altimeter is not noticeable. But at CW6266's elevation of 6883', the difference would be noticeable. The problem is that your calibration offset under that method represents the difference between the raw pressure and the altimeter (pressure adjusted for elevation). However, the offset you enter is a fixed value. The actual altimeter formula results in a varying delta between raw pressure and altimeter over the range of raw pressure values you could see in a weather station. At 6883 feet, even just a 3 mb change in the raw pressure would result in 0.7 mb change in the delta between the raw pressure and the altimeter. At higher altitudes, it really is best to just properly calculate the altimeter, and send that to CWOP. Steve SoftWx >Steve didn't mention it, but he wrote a handy program to back >track the VP SLP calculation to altimeter pressure: >http://www.softwx.com/weather/vppressurecalc.html >Your problem is a simple matter of you are trying to correct >SLP pressure and you'll chase that forever, unless you take >steps to report altimeter pressure. I started down that path, >but soon realized it'd never work. Set altitude to zero and >set an offset, I wish it had another decimal place, but I now >stay well within 1mb of what MADIS expects: >http://weather.gladstonefamily.net/site/C5250 From wx at w0lta.net Thu Sep 20 10:51:45 2007 From: wx at w0lta.net (Rick Patterson) Date: Thu, 20 Sep 2007 09:51:45 -0600 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: <003d01c7fb5d$f89bf850$e9d3e8f0$@com> Message-ID: My station ( http://weather.gladstonefamily.net/site/AR797 )was getting red check marks nearly every day after I had installed it. I would chase this station or that station, constantly fiddling with what ever adjustments I though would work. One day the following e-mail came over this list. I followed Evans advice and now a year + later I have been getting green check marks. Thanks and happy weather reporting Rick Patterson Shameless self promotion. www.w0lta.net http://w0lta.net/weather/Current_Vantage_Pro.htm > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Evan > Bookbinder > Sent: Sunday, July 23, 2006 7:46 PM > To: Discussion of weather data quality issues > Subject: [wxqc] Davis VP barometer clarification > > > Obviously, there is still a lot of confusion out there from what exactly > needs to be done to get the Davis VP2 barometer correct both internally and > in terms of transmitting to CWOP/APRS. I hope these instructions will remove > a lot of the QC problems we're seeing. > > Console: > > - Set your elevation in the console to the elevation of the console > itself. For example, my house at ground level is 968 feet, and the console > is sitting in my 2nd floor office next to the computer -- at a height of 980 > feet. > > - Although indoor temperature flucutations are generally minor, let the > unit sit for a good 12-14 hours. > > - Next, adjust the console as necessary to the SEA LEVEL PRESSURE of the > nearest official observation site (or an interpolation between two). Note > that I said SEA LEVEL PRESSURE, as this is what is displayed on the console > (a very useful meteorological value). How do we do this? Here's the easiest > way I've found. > > 1.) http://www.uswx.com/us/wx/ > 2.) Click on your state > 3.) On the left hand side menu, click the purple "Stations" link > 4.) You will see a list of all the official weather stations in your > state. Click on the 4 letter identifier for the observation sites closest to > your location. > 5.) Making sure that the observation is current, you will see the > "Pressure" item in the table, which correctly uses the Sea Level Pressure > for that site. They display the pressure in both millibars (which I prefer > to display on my console) or inches of mercury. Your console should be > adjusted to THIS number (or interpolated between surrounding sites). It's > always recommended that you pick a day with light wind, which should > correspond to similar pressure readings in your area. > 6.) NOTE: DO NOT use the Axxxx group in a coded METAR observation, or > the pressure given by calling into an airport observation site. These are > altimeter settings, and not what is required on the Davis VP2 console. > > - From here on out, your console should run smoothly in tandem with the > official observation sites. My console is generally dead on or about 0.1 mb > different from the nearby airport site, exactly what we want to see. > > > CWOP/APRS: > > Now, for whatever reason, CWOP/APRS uses altimeter setting, NOT Sea > Level Pressure as noted above. This may be due to the limitation of other > manufacturer's instruments reporting into the network. In any event, and as > discussed in previous threads, these are not one in the same. Altimeter > setting is primarily used for aviation purposes, while sea level pressure > (adjusted for temperature) is used for meteorological purposes. > > Now, theoretically, you should have to do nothing further here. The > software you are using to send CWOP/APRS data *should* internally calculate > the altimeter setting from your console's sea level pressure data and > transmit it. > > Again, MAKE SURE THAT YOU ARE USING SOFTWARE THAT SENDS ALTIMETER > SETTING DATA. If you are unclear, contact the software's author and make > sure that they are calculating this correctly. > > VPLive works fantastic, as does WeatherLink 5.7. > > ***** For those using WeatherLink 5.6 or lower (which is a fairly common > problem from what I've seen), PLEASE make sure that you upgrade to V5.7 > immediately. http://www.davisnet.com/support/weather/software.asp#vantagePro > ***** > > Only V5.7 correctly sends altimeter setting. V5.6 and earlier versions > incorrectly sent the sea level pressure directly from the console. > > As a plea to Davis, in the APRS data string, it would really be nice to > see the software version number included with the generic "DsVP" in future > updates. This really makes troubleshooting a lot easier -- for example > "DsVP57". > > > Respectfully, > Evan Bookbinder > Senior Meteorologist > NWS Kansas City/Pleasant Hill MO > > _______________________________________________ -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Steve Hatchett Sent: Thursday, September 20, 2007 2:12 AM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Frequency of barometer adjustment I just wanted to note that using the technique of setting the console elevation to 0 (which turns off the SLP calculation from occurring in the console) and then setting a fixed calibration offset to adjust for elevation, while better than reporting SLP, it is not quite the same as reporting true altimeter. At Keith's lower elevation (under 1000') the difference is probably between the zero elevation method and true altimeter is not noticeable. But at CW6266's elevation of 6883', the difference would be noticeable. The problem is that your calibration offset under that method represents the difference between the raw pressure and the altimeter (pressure adjusted for elevation). However, the offset you enter is a fixed value. The actual altimeter formula results in a varying delta between raw pressure and altimeter over the range of raw pressure values you could see in a weather station. At 6883 feet, even just a 3 mb change in the raw pressure would result in 0.7 mb change in the delta between the raw pressure and the altimeter. At higher altitudes, it really is best to just properly calculate the altimeter, and send that to CWOP. Steve SoftWx >Steve didn't mention it, but he wrote a handy program to back >track the VP SLP calculation to altimeter pressure: >http://www.softwx.com/weather/vppressurecalc.html >Your problem is a simple matter of you are trying to correct >SLP pressure and you'll chase that forever, unless you take >steps to report altimeter pressure. I started down that path, >but soon realized it'd never work. Set altitude to zero and >set an offset, I wish it had another decimal place, but I now >stay well within 1mb of what MADIS expects: >http://weather.gladstonefamily.net/site/C5250 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From wx at w0lta.net Thu Sep 20 12:04:16 2007 From: wx at w0lta.net (Rick Patterson) Date: Thu, 20 Sep 2007 11:04:16 -0600 Subject: [wxqc] Frequency of barometer adjustment In-Reply-To: Message-ID: One additional piece of information on finding the nearest reporting station to you can be found by using this url. Just substitute your station id for mine. http://weather.gladstonefamily.net/site/AR797?;asosonly=1 Thanks and happy weather reporting Rick Patterson Shameless self promotion. www.w0lta.net http://w0lta.net/weather/Current_Vantage_Pro.htm -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Rick Patterson Sent: Thursday, September 20, 2007 9:52 AM To: Discussion of weather data quality issues Subject: Re: [wxqc] Frequency of barometer adjustment My station ( http://weather.gladstonefamily.net/site/AR797 )was getting red check marks nearly every day after I had installed it. I would chase this station or that station, constantly fiddling with what ever adjustments I though would work. One day the following e-mail came over this list. I followed Evans advice and now a year + later I have been getting green check marks. Thanks and happy weather reporting Rick Patterson Shameless self promotion. www.w0lta.net http://w0lta.net/weather/Current_Vantage_Pro.htm > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Evan > Bookbinder > Sent: Sunday, July 23, 2006 7:46 PM > To: Discussion of weather data quality issues > Subject: [wxqc] Davis VP barometer clarification > > > Obviously, there is still a lot of confusion out there from what exactly > needs to be done to get the Davis VP2 barometer correct both internally and > in terms of transmitting to CWOP/APRS. I hope these instructions will remove > a lot of the QC problems we're seeing. > > Console: > > - Set your elevation in the console to the elevation of the console > itself. For example, my house at ground level is 968 feet, and the console > is sitting in my 2nd floor office next to the computer -- at a height of 980 > feet. > > - Although indoor temperature flucutations are generally minor, let the > unit sit for a good 12-14 hours. >