Notes:
The purpose of REGRID is to read archived meteorological analyses on pressure levels and interpolate those analyses from some native grid and map projection to the grid and map projection defined by the MM5 preprocessor program TERRAIN. REGRID handles pressure-level and surface analyses. Two dimensional interpolation is performed on these levels. Other sorts of levels, such as isentropic levels or model sigma or eta levels are not handled.
REGRID is the second step in the flow diagram of the MM5 modeling system. It expects input from the TERRAIN program, and creates files ready for RAWINS, LITTLE_R, or INTERPF. These files are generally used as the first guess to an objective analysis (RAWINS or LITTLE_R), or as analyses which are to be directly interpolated to the MM5 model levels for initial and boundary conditions for MM5 (INTERPF).