Cumulus Support

10 consecutive readings of wind chill:
Watson Cumulus
2.8 3.0
3.4 3.3
2.3 2.8
3.9 3.5
0.7 2.3
3.4 3.3
2.3 2.8
-1.7 1.4
0.4 2.2
0.7 2.3
Cumulus has smaller fluctuations than the box.
Ib

Just re-read Jim Easterbrook's paper re the Easyweather.dat file.
He was apparently unable to figure out the formula behind the wind chill numbers for the Fine Offset station
He does not explain the raw data received from the box. I am sure you have a description.
Would you be kind enough to publish it, e.g. in the Wiki?
Ib

The spec I work from is simply a memory map in the form of an excel spreadsheet; I'll attach it here.

Thanks. Looks complicated
I'll try to figure out what it means and how to interpret the raw data.
Ib

It's not completely self-explanatory. I'll post a bit of info later that will help. Cumulus actually uses very little of what you see in the spreadsheet.

Regarding the wind chill; I've checked the code in Cumulus, and it's using the 'new' wind chill formula, as used by the US and Canadian weather services since 2001. I haven't been able to find out what the UK Met Office use, if indeed they specify a standard. I think they have their own formula, but don't tend to use wind chill very much anyway. The formula that Cumulus uses is the same formula as in Steve Hatchett's weather utils.

So I'm confident that Cumulus is "correct", and that the station is using some other formula, so I won't be taking this any further.

http://www.softwx.com/weather/uwxutils.html
http://www.weather.gov/os/windchill/index.shtml
http://www.msc.ec.gc.ca/education/windc ... ions_e.cfm
http://en.wikipedia.org/wiki/Wind_chill