Author Topic: Wind Chill Calculation  (Read 1006 times)

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Offline geno

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Wind Chill Calculation
« on: February 11, 2012, 12:34:34 PM »
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

Geno

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Offline W3DRM

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Re: Wind Chill Calculation
« Reply #1 on: February 11, 2012, 01:11:42 PM »
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.

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Offline geno

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Re: Wind Chill Calculation
« Reply #2 on: February 12, 2012, 09:25:30 AM »
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.
Geno

Davis Vantage Vue -- Feb, 2011
VWS 14.01 p33
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Offline W3DRM

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Re: Wind Chill Calculation
« Reply #3 on: February 12, 2012, 07:17:54 PM »
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:


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:




« Last Edit: February 12, 2012, 07:28:41 PM by W3DRM »
Don - W3DRM - Minden, Nevada --- Blitzortung ID: 808
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Offline Weather Display

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Re: Wind Chill Calculation
« Reply #4 on: February 13, 2012, 12:58:05 PM »
50F(10C) is the cut off, not 40F

Offline W3DRM

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Re: Wind Chill Calculation
« Reply #5 on: February 13, 2012, 02:07:19 PM »
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.

Don - W3DRM - Minden, Nevada --- Blitzortung ID: 808
Davis Wireless VP2, VWS 15.00 p01,
StartWatch, VirtualVP, VPLive, WL 5.9.3, Image Salsa, Win7 Ultimate-SP1
--- Logitech QuickCam Fusion webcam