Wind Chill Calculation

[geno]

It's finally cold in Atlanta and the wind is really kicking up.  I checked my weather station to see what the wind chill was and the program shows the ambient temp and wind chill as the same.  Wind of 12 mph should make a difference.  Since this calculation is being done inside the program (I think) what might be the problem?

Thanks,
-gene
www.genesweather.info

[W3DRM]

Appears to be working from what I can tell. I see a temp of 36.4 and a Wind Chill of 35.8 with the wind at 2mph. That sounds reasonable to me.

[geno]

Thanks for the reply.  What I discovered is that there is a new calculation for computing wind chill.  And, if the wind speed is relatively low, it will have little or no impact on the wind chill reading.  Do a Google search for wind chill calculator to obtain the new formula.  I put both in an Excel spreadsheet to see the difference using the same parameters.

[W3DRM]

Thanks for the reply.  What I discovered is that there is a new calculation for computing wind chill.  And, if the wind speed is relatively low, it will have little or no impact on the wind chill reading.  Do a Google search for wind chill calculator to obtain the new formula.  I put both in an Excel spreadsheet to see the difference using the same parameters.

Yes, NWS began using a new Wind Chill calculation in November 1, 2001. A link to their website that includes a built-in Wind Chill calculator is as follows:

• http://www.nws.noaa.gov/om/windchill/

NOTE: The wind chill formula is only good when the wind is above 3mph and below 110mph.

Also, wind chill is only valid for temperatures of 40 degrees F and below.

UPDATED: 2/12/2012@ 4:25pm PT

Here is another link that shows both Wind Chill and Heat Index which is based on Temp and Rel Humidity:

• http://www.erh.noaa.gov/er/iln/tables.htm

[Weather Display]

50F(10C) is the cut off, not 40F

[W3DRM]

50F(10C) is the cut off, not 40F

Oops, that was a typo. To be fully accurate the temp range has to be above -50F and less than +50F.