[wxqc] Local elevation effects on QC graphs

[Mark W]

Hi all,
    My temperature has been off by quite a bit as compared to the QC graphs, and I was wondering if elevation is taken into account for temperature deviations. Most of the surrounding stations are 700-800ft below me and as expected I have lower temps more often then not, but in the evening when cool air pools in the lower areas, I have higher temperatures.

In particular yesterday really showed this since we also had a local rain shower at the end of the day.

http://pond1.gladstonefamily.net:8080/cgi-bin/wxqchart.pl?site=C3833

The temperature on my hill didn't get near as cool as the elevations below me. I was wondering if in cases like this is the weather info rejected?

There is a reject day on my sensor array and that is due to the fact we had sun while persistent clouds were in other places, on top of the fact we started warmer right in the morning:

http://weather.gladstonefamily.net/site/C3833

I cannot imagine the daunting task of determining if the data is good or not. Soo many specific cases can cause a dataset on a particular day to fail.Why does it only analyze a day? What about a running average error rate over a period of days where the oldest time has the least impact, and the latest time has the most. Something akin to the old formula

Y = Y - Y / numPoints + newSample

And Y will eventually result in newSample times numPoints as data is passed through it. Divide by numPoints and you have a infinite averaging filter weighting the lastest samples the most. Changing the numPoints effects the amount of averaging.

I used a method like this to solve air-pressure changes to detect trends where the newSample was actually the difference between two adjacent points. Then I didn't have to store all of the points and sum them all to find the slope over a period of time. Then it was easy to take the output on a real-time system with very little computational overhead.

The reason why I bring this up is while day to day events can be highly variable from location to location, averaging over a week would make more sense I would think.

Just a thought.

p.s. I don't like those little red crosses ;-)

-Mark
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