Topic: VPLive & CWOP barometer settings

[W3DRM]

Since I have just installed VPLive, I am getting many CWOP data quality error messages indicating my data is out of tolerance. Prior to using VPLive, I was using VWSaprs to create and upload the CWOP data. I am also at an elevation of 4801' and found myself constantly chasing (manually adjusting the VP2 console barometer reading) so it matched the local airport altimeter readings. Needless to say this was a never ending job. Now that I have installed VPLive it is my understanding that it will automatically adjust the barometer readings being reported to CWOP based on my elevation, the current barometer reading and temperature. My question is this - since I have been manually adjusting the barometer so it matched the local airport altimeter reading (obtained via my scanner) how do I reset my barometer reading so it correctly reads what it should?

Hope I am making some sense here. If not, please tell me what I need to be giving for information. I have used the VpPressureCalc routine and changed the barometer reading until the MADIS altimeter reading matched what the local airport was reporting. However, CWOP quality data reports show me to be way off. You can see the reports at the following URL:
.....http://weather.gladstonefamily.net/site/AS061

[Mark / Ohio]

I would let it run for a day or two and see what happens.  Your last data looks pretty good to me.  VPLive takes into account some past data to make the calculations.  If it was unable to find the data in the WeatherLink files I believe it takes about 12 hours or so to stabilize.

VPlive shows my baro. offset is 0.046inHg.  I tweaked it several times over a week or two trying to get close to the local airport averages.  I set the baro using WeatherLink direct to the console and not through VVP.  I used WeatherLink only because at the time I was more familar with it than VWS.  But either way I think your best, at least with the current version of VVP, to make the basic calibration settings direct and not through Virtual VP.

[tinplate]

I think Mark's right. Your barometer now looks right on.
http://weather.gladstonefamily.net/qchart/AS061?date=20060914&addnl=KRNO&Add+to+charts=Add+to+charts&.cgifields=addnl

another link (hold mouse over station to see most recent readings):
http://www.wrh.noaa.gov/mesowest/mwmap.php?map=renos

I picked reno instead of the closer tahoe stations because reno's closer to your elevation and probably has better equipment. You really should compare to a good NWS/FAA station in case any of the CWOP stations are feeding bad data.

The reason the standard deviation and other measure are still showing bad is because they are including data from before the time you got VPLive up and running. Once your old data scrolls off, that should come in line.

At your elevation, I think you'll notice a big improvement in the stability of your altimeter in the QC.

Steve

[W3DRM]

Thanks Mark & Steve,

I'll continue to watch it and see how it stabilizes. I can't use the Tahoe readings (KTVL) due to the difference in altitude and Reno is about 35 miles north of me and can have totally different weather than us at the same time. I'm about 400 feet higher than the nearest airport (Minden-Tahoe) which has an automated weather report on 119.325MHz which is what I have been trying to adjust my station readings to. It's only 3 miles or so SW from me.