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Author Topic: MADIS claims barometer failing spatial consistency  (Read 1545 times)

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Offline Bigbaywx

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MADIS claims barometer failing spatial consistency
« on: September 05, 2016, 09:53:05 AM »
Hi all;

Love the new Davis equipment but the MADIS checks in the CWOP claim that my barometer is reading way to low.  I have the site altitude inputted correctly as that was my first thought. 

[Link to CWOP page from my website:   http://www.bigbaywx.com/weather28/index.php?p=wsPartners&s=cwop&lang=en#data-area]

I disagree with their assessment for a couple of different reasons.  The Davis equipment seems to be more accurate than the cheap Lacrosse equipment that I was using before to begin with.  Secondarily going to the Davis weather link map with my stations and showing other stations in the area:  http://www.weatherlink.com/map.php?station=bigbaywx  show that my station barometer is pretty close to the other Davis stations in the area and thirdly by going to the buoy page from my website:  http://www.bigbaywx.com/weather28/index.php?p=34&lang=en#data-area   , the other buoy's in the area including the NWS ones shows that my barometer reading is right in line with the other stations.

And then if you go back to the CWOP page and look at the neighboring stations reporting to CWOP and look at their barometer readings it shows that some are higher and others are lower than what I'm reporting.  I really don't want to adjust my barometer higher to satisfy MADIS when because of the other reasons I've given my station seems to be in line with others in the area.  Anyone have experience with MADIS anomalies or have any ideas why their system would show me as being off?

Thanks!!

Offline NorCal Dan

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Re: MADIS claims barometer failing spatial consistency
« Reply #1 on: September 05, 2016, 02:54:11 PM »
Do not chase the MADIS "error" and make changes to your station.  If your data is correct then just ignore that "error".

Add:  Here is one problem that is skewing the readings:

http://weather.gladstonefamily.net/qchart/C9114?date=20160905&addnl=BIGM4&addnl=YDRM4&Add+to+charts=Add+to+charts&.cgifields=addnl

The BIGM4 station barometer is suspect.
« Last Edit: September 05, 2016, 03:03:22 PM by NorCal Dan »

Offline niko

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Re: MADIS claims barometer failing spatial consistency
« Reply #2 on: September 05, 2016, 03:40:43 PM »
Do not chase the MADIS "error" and make changes to your station.  If your data is correct then just ignore that "error".

Exactly! "That way madness lies."

Offline Bigbaywx

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Re: MADIS claims barometer failing spatial consistency
« Reply #3 on: September 05, 2016, 04:48:56 PM »

The BIGM4 station barometer is suspect.

Ahh...

Thanks for that Dan I didn't realize that their barometer was so far off.  That is a NWS barometer as well.  I guess they should be recalibrating their own equipment from time to time.  And if MADIS is using nearby NWS and other official barometers to use for their analysis then it makes sense.  i'll take the advice and ignore MADIS for the time being.  IIRC I had to jack up my cheap Lacrosse unit's barometer by a few mb a couple of years ago to bring it in line with MADIS so that BIGM4 system might have been out of whack for quite awhile.  With the other local Davis stations having readings really close to mine I had a hard time believing that mine was out of sorts.

Thanks again!

Offline hydrowx

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Re: MADIS claims barometer failing spatial consistency
« Reply #4 on: September 05, 2016, 05:51:38 PM »
Your barometer of 29.87 seems to match close enough to the 29.85 being reported now by the GLOS site.  I couldn't get that cwop link you posted to load and I don't see a Big Bay MI on the CWOP Michigan list so I may be missing something here. But yes, the nearest neighbor approach to QC only works when all surrounding stations are providing good data.
Bill


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