Storm relative radial/tangential wind

[jrleeman]

Calculate the storm relative radial/tangential wind, the equivalent of GEMPAK's MTNG, MRAD.

From GEMPAK Docs:

MTNG  Magnitude of storm relative tangential wind
      MTNG ( V, LAT, LON, DIR, SPD ) = DOT ( Vrel, k X R )
             where Vrel is the velocity minus the storm motion vector
             specified by DIR and SPD, and R is a unit vector
             tangent to a great circle arc from the storm center
             specified by LAT, LON to a grid point.  k denotes the
	     local vertical unit vector.

MRAD  Magnitude of storm relative radial wind
      MRAD ( V, LAT, LON, DIR, SPD ) = DOT ( Vrel, R )
             where Vrel is the velocity minus the storm motion vector
             specified by DIR and SPD, and R is a unit vector
             tangent to a great circle arc from the storm center
             specified by LAT, LON to a grid point.

[jbzambon]

If anyone is looking for this function, I put together some scripts that may be helpful.