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>From: Kurt Buffalo <address@hidden> >Organization: UCAR/Unidata >Keywords: 200401162156.i0GLuDp2009126 >Hello, > >I'm a graduate student at Texas A&M University and I'm using NSHARP for >some of my M.S. thesis work. I'm looking for some documentation on how >the various parameters output by NSHARP are computed. I would greatly >appreciate it if you could point me towards any such documentation. In >particular, I'm most interested in how the storm motion is computed. > >Thanks, >Kurt Buffalo > > Kurt, Since NSHARP was developed as an external application at the NSSFC, the documentation available on it is less than the core GEMPAK libraries. I believe your answer lies in the code: $NAWIPS/nprogs/nsharp/source/xwvid6.c Here the code shows in several locations the calculation of st_dir and st_spd (storm motion components) as: mean_wind( sndg[sfc()][1], i_pres(msl(6000.0F)), &ix1, &ix2, &st_dir, &st_spd); st_spd *= .75F; st_dir += 30.0F; if(st_dir>360.0F) st_dir -= 360.0F; printf( "storm motion = %f/%f\n", st_dir, st_spd); This calculates the mean wind in the sfc to 6000m layer, and then adjusts the speed by 75% and adds a 30 degree (eg Ekman) component to the wind. The code doesn't have a reference to this calculation, so I would suggest looking at relevant liturature and the SPC as well. Steve Chiswell -- NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publically available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.