GRIB Variable Lookup File (grib_var.lup and grib2_var.lup)

The GRIB variable lookup file links between GRIB parameter defined in the product definition section and a variable name and its units. In GRIB version 1, there are three parameters that determine a variable:

Grid source - who generated the GRIB file
Parameter table version - typically either 2 or 3
Parameter indicator - number between 0 and 255

In GRIB version 2, there are four parameters that define a variable:

Grid source - who generated the GRIB file
Parameter discipline - whether its a meteorological, hydrological, space or oceanographic product
Parameter category - whether it's temperature, moisture, momentum, etc
Parameter indicator - number between 0 and 255

FORMAT

Both lookup files are formatted the same:

p1   p2   p3   p4  Name  Unit  Description

Where:

p1 = First parameter - version for GRIB1 (always 1), source for GRIB2
p2 = Second parameter - source for GRIB1, discipline for GRIB2
p3 = Third parameter - table version for GRIB1 - category for GRIB2
p4 = Foiurth parameter - parameter indicator
Name = Abbreviated name - link to variable.lup file
Unit - Units
Description - not used but informative

Here is a sample of the GRIB version 1 "grib_var.lup" file:

# Ver Src Tab Par  Name   Unit
  1    0   0   1   pres   Pa      Pressure
  1    0   0   2   slpres Pa      SL Pressure
  1    0   0   3   ptend  Pa/s    Pressure tendency
  1    7   2   4   pvort  Kgm^2/kg/s Potential vorticity
  1    7   2   5   icaht  m       ICAO Stand Atmos height
  1    0   0   6   geop   m^2/s^2 Geopotential
  1    0   0   7   hght   gpm     Geopotential Height
  1    0   0   8   ht     m       Height
  1    0   0   9   stdht  m       Std dev Height
  1    7   2  10   ozone  Dobson  Total ozone
  1    0   0  11   temp   K       Temperature
  1    0   0  12   vtemp  K       Virtual temperature
  1    0   0  13   theta  K       Potential temperature

Here is a sample of the GRIB version 2 "grib2_var.lup" file:

#Src Dis Cat Par Name    Unit 
  0   0   0   0  temp    K      Temperature
  0   0   0   1  vtemp   K      Virtual temperature
  0   0   0   2  theta   K      Potential temperature
  0   0   0   3  thetae  K      Equiv potential temperature
  0   0   0   4  maxt    K      Maximum temperature
  0   0   0   5  mint    K      Minimum temperature
  0   0   0   6  dewp    K      Dewpoint temperature
  0   0   0   7  dewd    K      Dewpoint depression
  0   0   0  10  lheat   W/m^2  Latent heat flux
  0   0   0  11  sheat   W/m^2  Sensible heat flux
  0   0   0  12  heat    K      Heat index
  0   0   0  13  wchill  K      Wind chill factor
  0   0   0  21  aptmp   K      Apparent temperature
...
  0   0   1   0  shum    kg/kg  Specific humidity
  0   0   1   1  rhum    %      Relative humidity
  0   0   1   3  pwat    kg/m^2 Precipitable water
  0   0   1   6  evap    kg/m^2 Evaporation
  0   0   1   7  prrate  kg/m^2/s Precipitation rate
...
  0   0   1  37  cprate  kg/m^2/s Convective precip rate
  0   0   1  39  cpofp   %      Percent of frozen precipitation
  0   0   1  42  snwcov  %      Snow cover
  0   0   1  74  tcolg   kg/m^3 Total column graupel
  7   0   1 192  crain   -      Category rain
  7   0   1 193  cfzrn   -      Category freezing rain
  7   0   1 194  cicep   -      Category ice pellets
  7   0   1 195  csnow   -      Category snow

GRIB Variable Lookup File (grib_var.lup and grib2_var.lup)

FORMAT

SEE ALSO