[gradsusr] Wind direction in degrees at 10 meters

[Salvador Salazar]

Hi guys,

Several questions have been asked about plotting wind direction in
degrees at 10 meters, but the scripts I found so far are giving me
funny results. Further, ARWpost doesn't seem to throw this variable
out, although it does throw wind direction at the z levels. I'm
posting the script below, hopefully someone can spot the error:

'define dir=atan2(-u10,-v10)*180/3.141592654'
'define dir=const(dir,1)*(const(maskout(dir,dir),0,-u10)+const(maskout(360+dir,-dir),0,-u10))'

The problem with the above script is that it's telling me my model had
Southern winds in the beginning, when I know it had North/Northeast
winds from simply looking at the vectors u10 and v10. So, hopefully it
just has a negative somewhere it doesn't belong or some other trivial
error.