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Darrell, You should be able to use ALTM. See the GEMPAK support archives response: http://www.unidata.ucar.edu/glimpse/gempak/3655 as well as the SFPARM section of chapter 3 of the user guide and appendix A. The mean column reduction is used for sea level. Steve Chiswell Unidata User Support On Mon, 3 Jul 2000, Darrell Ensley wrote: > > Does anyone know of a 'pre-defined' way in GEMPAK > to convert ALTI to PMSL? > > I've got some Mexican surface data GEMPAK files with > ALTI but no PMSL. Am I going to need to take the SELV > and convert to PMSL using Standard Atmosphere myself? > Or is there a way to do this in GEMPAK already...or > any other 'non-manual' ways to do this? > > Thanks! > > Darrell > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Darrell Bryan Ensley <address@hidden> > Mesoscale Dynamics Lab 5703 Windlestraw Dr. > Rm 135, Research III Apartment 37 > North Carolina State Univ. Durham, NC 27713 > W: (919) 515-1437 H: (919) 361-1346 > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >