WRF - Developmental Testbed Center

write(unit=ounit) startloc, startlat, startlon, dx, dy, &truelat1, earth_radius! Lambert conformalelse if (iproj == 3) thenwrite(unit=ounit) hdate, xfcst, map_source, field, &units, desc, xlvl, nx, ny, iprojwrite(unit=ounit) startloc, startlat, startlon, dx, dy, &xlonc, truelat1, truelat2, earth_radius! Gaussianelse if (iproj == 4) thenwrite(unit=ounit) hdate, xfcst, map_source, field, &units, desc, xlvl, nx, ny, iprojwrite(unit=ounit) startloc, startlat, startlon, &nlats, deltalon, earth_radius! Polar stereographicelse if (iproj == 5) thenwrite(unit=ounit) hdate, xfcst, map_source, field, &units, desc, xlvl, nx, ny, iprojwrite(unit=ounit) startloc, startlat, startlon, dx, dy, &xlonc, truelat1, earth_radiusend if! 3) WRITE WIND ROTATION FLAGwrite(unit=ounit) is_wind_grid_rel! 4) WRITE 2-D ARRAY OF DATAwrite(unit=ounit) slabCreating and Editing VtablesAlthough Vtables are provided for many common data sets, it would be impossible forungrib to anticipate every possible source of meteorological data in GRIB format. Whena new source of data is to be processed by ungrib.exe, the user may create a new Vtableeither from scratch, or by using an existing Vtable as an example. In either case, a basicknowledge of the meaning and use of the various fields of the Vtable will be helpful.Each Vtable contains either seven or eleven fields, depending on whether the Vtable isfor a GRIB Edition 1 data source or a GRIB Edition 2 data source, respectively. Thefields of a Vtable fall into one of three categories: fields that describe how the data areidentified within the GRIB file, fields that describe how the data are identified by theungrib and metgrid programs, and fields specific to GRIB Edition 2. Each variable to beextracted by ungrib.exe will have one or more lines in the Vtable, with multiple lines fordata that are split among different level types – for example, a surface level and upper-airlevels. The fields that must be specified for a line, or entry, in the Vtable depends on thespecifics of the field and level.The first group of fields – those that describe how the data are identified within the GRIBfile – are given under the column headings of the Vtable shown below.WRF-NMM V3: User’s Guide 3-26