[wxqc] wxqc Digest, Vol 42, Issue 18

[webmaster]

Hello Keith,

>CWOP only collects the data, MADIS then does the QC checks and
>flags bad data as such. If someone is using data that is flagged
>as questionable, that's their error.
>
>I assume you where refering to AR868:
>http://www-frd.fsl.noaa.gov/mesonet/?center_lon=-93.18331&center_lat=4
>4.64612&scale=880
>Is centered on your location. If you click on the AR868 marker,
>The temperature data for that station is marked as having passed
>stage 1, failed 2 or 3. Which means it passed the sanity check,
>but failed temporal and internal consistency checks or the spatial
>consistency checks. In reality, it looks they have a stuck sensors
>problem.
>
>Bad data is saved, because it may be possible to correct for an
>error.

Yes, that does appear to be the station....how many IDs can a station have?

When I viewed the station in WB it had an ID something like NPD08 or 
something like that.  Since I am unable to get the WB page to display 
I can't see what WB shows them as now.  If I bring up the station 
with Weather Exchange Neighborhood watch they have another ID, 
MC0796.  There are listed in Wunderground as:

http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=MC0796

You will see Wunderground shows the same "stuck" 65 degrees that WB 
did yesterday.

According to MADIS their elevation is also way off.  They have lots 
of problems.

http://weather.gladstonefamily.net/site/KLVN

That is the local airport that has been consistently several degrees 
off and even after talking to the FAA technicians responsible for the 
station the problem hasn't been corrected.

I am still curious why these programs don't filter out known bad 
data.  It would cause me to lack confidence in the program if they 
don't know to remove known bad data.  Like a grocer that leaves 
rotten fruit on the shelf.  The grocer could tell you that you know 
not to take the rotten fruit and only take good fruit.  I would 
rather not have to pick around rotten fruit to get the good 
fruit.  Likewise, I think weather programs, whether it be CWOP, WB, 
or whatever should have logic built in to disgard bad data.  I am not 
saying disgard historical data, but if a station has a stuck 
thermometer there is no opportunity to substitute good data as the 
wouldn't have good data to substitute.

As far as I am concerned all programs showing "current" data ought to 
discard data from both of those stations until they get corrected.

> > 3.  Does anyone know why some of the weather stations like mine and
> > the nearby CW5773 show in the exact position but the airport's
> > position is WAY wrong?
> >
>
>Different sources have different locations recorded:
>http://weather.gladstonefamily.net/site/KLVN?tile=10;showall=1

Thanks for pointing that out....one of the sources is called ISH and 
it is ISHY.....in the ISH database the station is listed twice:


726562 04943 AIRLAKE ARPT                  US US MN KLVN  +44628 -093218 +02926
726562 99999 AIRLAKE ARPT                  US US MN KLVN  +44617 -093217 +02930

They are both WAY wrong and it is one of these wrong values that is 
being used by WB.

BTW, for some reason I was able to properly view WB yesterday with 
Internet Explorer and today I can't.  I brought up Firefox and it 
shows WB fine?

Any clues as to what is up with IE and how to correct it?

Thanks!

Lew


******************************************
Lew - Amateur Weatherman
lew at farmingtonweather.com
Farmington Weather
www.farmingtonweather.com
Farmington, Minnesota, USA 
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