20020903: NCEP model changes-

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: 20020903: NCEP model changes-
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Tue, 03 Sep 2002 08:11:14 -0600

ROM:             John H. Ward
                 Chief, Production Management Branch

SUBJECT:          Changes to the NWS Production Suite



    The implementation of the T254 Global Forecast System (GFS)
is tentatively rescheduled for Tuesday, 29 October.  The T254 GFS
requires approximately 20 additional minutes of wall-clock time
than the current T170 version.  The impact of this change on the
NCEP production schedule will be as follows:

      GFS 120 hour products delayed 21 minutes
      GFS 384 hour products delayed 21 minutes
      GFDL Hurricane model delayed 25-30 minutes
      Wave model products delayed 25 minutes
      AVN MOS products delayed 21 minutes
      1200 UTC Global Ensemble products delayed 25 minutes

    When the next NCEP Central Computer System (CCS) becomes
operational in 2003, product delivery will return to the current
schedule.  Details of the upcoming change to the GFS can be found
at:

       http://sgi62.ncep.noaa.gov:8080/tpb97/TPB02/html/v1.html

    The GFS naming convention has created a degree of confusion
over the last few weeks.  The GFS is not a new model, it is new
terminology for the suite of applications (data collection,
analysis, model, etc.) currently identified as the Aviation (AVN)
Model run.  Plans are being developed to replace the AVN acronym
on the WEB and in the ftp server file structures.  Those changes,
however, will occur slowly over a lengthy period of time, with
ample notification and overlapping to provide sufficient time for
the transition.  No changes are expected prior to the completion
of the CCS conversion.  The transition to the next NCEP CCS has
began on a small, single node test system.  Production Management
Branch (PMB) has begun to move all operational codes and scripts
to the test system and perform an initial recompile and test of
the operational codes.  Individual programmers will only be
contacted if problems are encountered during these initial tests.
At this time production codes have not been frozen.  In early
October, all operational codes will be frozen while PMB
establishes parallel operations on the CCS.  The moratorium on
changes to the production suite can be expected to extend at
least through the normal holiday moratorium period.  All JIF's
for changes to be made prior to the moratorium should be
submitted by 1 September.  No implementations will be scheduled
for October, with the exception of the T254 GFS.  More details on
the transition and moratorium will be provided as they become
available.

    A list of the major model implementations planned for 2002
can be found at:

        http://www.nco.ncep.noaa.gov/pmb/changes

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