WRF - Developmental Testbed Center

RAINCV SNOW HBOTRAINNCVSNOWCNote: For WRF-ARW, the accumulated precipitation fields (RAINC and RAINNC)are run total accumulations.WPP Control File OverviewThe user interacts with wrfpost through the control file, parm/wrf_cntrl.parm. Thecontrol file is composed of a header and a body. The header specifies the output fileinformation. The body allows the user to select which fields and levels to process.The header of the wrf_cntrl.parm file contains the following variables:• KGTYPE: defines output grid type, which should always be 255.• IMDLTY: identifies the process ID for AWIPS.• DATSET: defines the prefix used for the output file name. Currently set to“WRFPRS”.The body of the wrf_cntrl.parm file is composed of a series of line pairs similar to thefollowing:(PRESS ON MDL SFCS ) SCAL=( 3.0)L=(11000 00000 00000 00000 00000 00000 00000 00000 00000 00000 0000000000 00000 00000)where,• the top line specifies the variable (e.g. PRESS) to process, the level type (e.g. ONMDL SFCS) a user is interested in, and the degree of accuracy to be retained(SCAL=3.0) in the GRIB output.o SCAL defines the precision of the data written out to the GRIB format.Positive values denote decimal scaling (maintain that number ofsignificant digits), while negative values describe binary scaling (preciseto 2^{SCAL}; i.e., SCAL=-3.0 gives output precise to the nearest 1/8).A list of all possible output fields for wrfpost is provided in Table 3. This tableprovides the full name of the variable in the first column and an abbreviated namein the second column. The abbreviated names are used in the control file. Notethat the variable names also contain the type of level on which they are output.For instance, temperature is available on “model surface” and “pressure surface”.• The second line specifies the levels on which the variable is to be posted.Controlling which variables wrfpost outputsTo output a field, the body of the control file needs to contain an entry for the appropriatevariable and output for this variable must be turned on for at least one level (see"Controlling which levels wrfpost outputs"). If an entry for a particular field is not yetWRF-NMM V3: User’s Guide 7-8