Here is an e6-b wind correction angle question: When I go to a site like aviationweather.gov and they give a wind direction at 3k feet such as 0220...do I need to correct for mag variation of the winds or is this already calculated?
The reason surface winds are reported as magnetic (rather than true as for winds aloft) is that the primary purpose for surface wind data is to select a runway for use, and runways are numbered with reference to magnetic north.
Aren't surface winds in METARs and TAFs given in True, and on ASOS/AWOS/ATIS over the radio in Magnetic?
Yup.
Dan
CH=TC +/- WCA +/- MV +/- deviation.
The order matters since your forecast winds are in TRUE. Lots of times people will take the true course, convert it to a mag course, and then apply the winds, which doesn't work out because the winds aren't in magnetic.
Hope this helps.
And only accurate to + - 180 degrees.And rounded
Don't forget to factor in the compass error!
He did, that was the "deviation" , the last item in the formula.