Using GrADS tools and NARR

[Jorge Luis Vazquez Aguirre]

Hello folks!

We are trying to use NARR data to study precipitation in Mexico. But when
using GrADS to read them the following issues had come... Any hints will be
greatly appreciated.

a) NCEPTAB 131

When we grib2ctl a NARR file (grib) we get this:
'Undefined parameter table (center 7-15 table 131) using NCEP-opn.

We downloaded the file nceptab_131 which looks like

-1:7:-1:131
0:var0:undefined
1:PRES:Pressure [Pa]
2:PRMSL:Pressure reduced to MSL [Pa]
3:PTEND:Pressure tendency [Pa/s]
4:PVORT:Pot. vorticity [km^2/kg/s]
5:ICAHT:ICAO Standard Atmosphere Reference Height [M]
6:GP:Geopotential [m^2/s^2]
7:HGT:Geopotential height [gpm]
8:DIST:Geometric height [m]
... etc.

but we do not know how to say to grib2ctl or wgrib that this table must be
used instead T62 or NCEP default. Do you know how?

b) NARR data are stored every 3 hours. In order to build daily datafiles we
get the sum of the files for hours 03,06,09,12,15,18,21, and 00 dy+1. Is it
correct?

Thank you very much

Jorge, Gaby, Rosa and Roberto.
Mexico.

_________________________________________________________________
Don't just search. Find. Check out the new MSN Search!
http://search.msn.click-url.com/go/onm00200636ave/direct/01/