[ Read Responses | Return to the Index ]

[ Previous | Next ]

Message: GRIB year/century encoding for Y2K

Posted by Stan Benjamin on 22 Dec 99, 8:04 MT

Here is a message from Geoff DiMego this morning about how the
GRIB PDS will handle year of century and century for RUC and other
NCEP GRIB files in the year 2000.


I received a question yesterday about the treatment of the year in
GRIB after Dec 31. Joe Johnson of NCEP's Central Operations has
provided a summary of the answer and a web site written by Cliff
Dey with the whole story. Here is Joe's answer:

Cliff Dey recently drafted an explanation on how the GRIB PDS will
specify octets 13 (year of the century) and 25 (century of initial
time). This info has been available in other documents disseminated,
but is being published again as a reminder and for those who didn't
receive the previous information. The explanation should be on the
NCEP WEB page (www.ncep.noaa.gov) today. However, to summarize:

I. For year 2000

 octet 13 - will contain a value equal to 100
 octet 25 - will contain a value equal to 20

II. For 2001

 octet 13 - will contain a value equal to 1
 octet 25 - will contain a value equal to 21

I hope this helps.

Joe Johnson

The FSL RAP/HRRR/RUC Information Forum is maintained with a variant of WebBBS .