UVMET does not correctly rotate winds to Earth coordinates for the rotated pole projection

[bladwig1]

For the rotated pole, the uvmet product does not perform any wind rotation. This behavior is correct for the standard lat/lon projection, but not when the pole is rotated. This is also broken in NCL and has been for years.

As a workaround, users should use the COSALPHA and SINALPHA variables and perform the rotation manually using:

u_earth = u * COSALPHA - v * SINALPHA v_earth = v * COSALPHA + u * SINALPHA