status africa data

Hiya,

As stated before, the NCEP data with multiple grids was split using 
LDM pqact actions. Since that's not possible for the africa data, the grid_id in the 
PDS section was used to split the data. But, the africa data had grid_id = 
255 for both grids so no split occurred. The data is organized according 
to forecast time, first grid has forecasts 6-240 and second grid 
has forecasts 246-360. The first grid has higher resolution then the 
second grid. I can probably modify a current program to do the split.

There is also a problem with the TOM_REALFORECASTS.20080112_v1_pf.grb grib
that has ~50 perturbations in the file. The variables look the same to the 
our grib reader because ECMWF uses local additions to the PDS section to 
distinguish the variables. Using the ECMWF decoder gribex, the following 
local use information was displayed.

ECMWF local usage identifier.               30
 Class.                                       1
 Type.                                       11
 Stream.                                   1035
 Version number or Experiment identifier.  0001

I don't know what this means but it probably identifies the variables so 
they aren't treated the same. According to the WMO documentation it 
states:

29-40   Reserved: need not be present
41-nn   Reserved for originating center use

So ECMWF is complying with the Grib1 specfications.

The other 3 types of ECMWF files don't contain the perturbations so they 
could be split according to forecast times.

My question, is where do I go from here?

Robb...



Section 1 - Product Definition Section.
 ---------------------------------------
 Code Table 2 Version Number.               128
 Originating centre identifier.              98
 Model identification.                      130
 Grid definition.                           255
 Flag (Code Table 1)                   10000000
 Parameter identifier (Code Table 2).       167
 Type of level (Code Table 3).                1
 Value 1 of level (Code Table 3).             0
 Value 2 of level (Code Table 3).             0
 Year of reference time of data.              8  (2008)
 Month of reference time of data.             1
 Day of reference time of data.              12
 Hour of reference time of data.              0
 Minute of reference time of data.            0
 Time unit (Code Table 4).                    1
 Time range one.                              6
 Time range two.                              0
 Time range indicator (Code Table 5)          0
 Number averaged.                             0
 Number missing from average.                 0
 Century of reference time of data.          21
 Sub-centre identifier.                       0
 Units decimal scaling factor.                0


ECMWF local usage identifier.               30
 Class.                                       1
 Type.                                       11
 Stream.                                   1035
 Version number or Experiment identifier.  0001


===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================