[wxqc] How are Station Analysis Graphs Derived?

[Merton Campbell Crockett]

I received a Davis Vantage Pro2 for Christmas and began reporting  
weather observations to CWOP in late January.  I am still trying to  
understand the quality control information that is being presented.

The quality control link on a weather station's findu web page takes  
you to a page that displays charts for barometric pressure,  
temperature, dew point, and relative humidity.  Each of the charts  
contains a graph of the weather station's observations in blue and a  
station analysis graph in red.

How are the station analysis graphs derived?

Are they based on regional- or meso- weather models?  Are they based  
on some sliding average of observations reported by the weather  
station or by a group of nearby weather stations?

At one point, I thought a model was being used based on astronomical  
sunrise as the station analysis showed rising temperatures two hours  
before direct sunlight would start heating the ground at approximately  
0830 in the morning.  Recently, however, the station analysis graph  
has become more accurate and this has piqued my curiosity about how  
the graphs are derived.

Merton Campbell Crockett
m.c.crockett at roadrunner.com