20020822: GFS-ADMIN NOTICE NOUS41 KWBC (fwd)

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: 20020822: GFS-ADMIN NOTICE NOUS41 KWBC (fwd)
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Thu, 22 Aug 2002 15:40:58 -0600

139
NOUS41 KWBC 222020
PNSWSH

PUBLIC INFO STATEMENT...TECHNICAL IMPLEMENTATION NOTICE 02-17
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
430 PM EDT THU AUG 22 2002

TO:       FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA WEATHER
         WIRE SERVICE /NWWS/ SUBSCRIBERS...EMERGENCY MANAGERS
         WEATHER INFORMATION NETWORK /EMWIN/ SUBSCRIBERS...
         OTHER NATIONAL WEATHER SERVICE /NWS/ CUSTOMERS AND
         PARTNERS...NWS EMPLOYEES

FROM:     HUA-LU PAN
         CHIEF...GLOBAL CLIMATE AND WEATHER MODELING BRANCH
         ENVIRONMENTAL MODELING CENTER /EMC/
         NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION /NCEP/

         AND

         JOHN WARD
         CHIEF...PRODUCTION MANAGEMENT BRANCH
         NCEP CENTRAL OPERATIONS /NCO/
         NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION /NCEP/

SUBJECT:  RESCHEDULED CHANGES TO THE HORIZONTAL AND VERTICAL
         RESOLUTIONS OF THE NCEP GLOBAL FORECAST
         SYSTEM...NOW EFFECTIVE OCT 29 2002 AT 1200 UTC

NOTE:  THE FOLLOWING CHANGES HAVE NO IMPACT ON NOAA WEATHER
WIRE SUBSCRIBERS

ON OCTOBER 29 2002 AT 1200 COORDINATED UNIVERSAL TIME /UTC/...THE
NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION /NCEP/ WILL CHANGE
THE HORIZONTAL AND VERTICAL RESOLUTIONS OF THE ANALYSIS AND
FORECAST SUITES IN ITS GLOBAL FORECAST SYSTEM /GFS/.  THE CHANGE
IN RESOLUTION IS THE FINAL STEP IN A CONSOLIDATION OF GLOBAL
MODEL JOBS...WHICH PREVIOUSLY INCLUDED ELIMINATION OF THE MEDIUM
RANGE FORECAST /MRF/ RUN...ON APRIL 24 2002...AND THE GENERATION
OF THE 4 PER DAY GFS /FORMERLY KNOWN AS THE AVN/ RUNS OUT TO 16
DAYS...ON MARCH 5 2002.

THE GFS WILL INCREASE ITS USE OF SATELLITE DATA...AND WILL CHANGE
ITS CURRENT T170...42-LAYER /T170L42/ RESOLUTION TO T254L64...
HORIZONTAL RESOLUTION CHANGES FROM 75 KM TO 55 KM...VERTICAL
RESOLUTION CHANGES PRIMARILY IN THE STRATOSPHERE...WITH MODEL TOP
RAISED FROM 2 HPA TO 0.2 HPA.

FORECAST MODEL SUITE...CURRENTLY T170L42 /0-180 HOURS/ AND T62L28
/180-384 HOURS/...WILL BECOME A DOWNWARD CASCADE OF RESOLUTIONS
FOR SHORT MEDIUM AND LONG RANGE FORECASTS...T254L64
/0-84 HOURS/...T170L42 /84-180 HOURS/ AND T126L28
/180-384 HOURS/.

USERS CAN EXPECT TO SEE SLIGHT IMPROVEMENTS IN MOST FORECASTS.
THE TROPICS MAY BE SLIGHTLY MORE NOISY.  MODEL BIASES AND OTHER
CHARACTERISTICS WILL REMAIN LARGELY UNCHANGED.  IT IS ANTICIPATED
THAT THE HIGHER RESOLUTION DURING THE FIRST 84 HOURS OF THE
FORECAST WILL IMPROVE MODELED DETAILS OF FRONTS...JET
STREAMS...PRECIPITATION...AND TROPICAL STORMS...WHILE THE HIGHER
RESOLUTION BEYOND 180 HOURS WILL IMPROVE FORECASTS OF
TRANSIENTS...THEREBY IMPROVING PREDICTIONS OF REGIME CHANGES.

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 CENTRAL COMPUTER SYSTEM BECOMES OPERATIONAL BY THE
THIRD QUARTER /APRIL...MAY...AND JUNE/ OF FISCAL YEAR 2003...THE
NCEP PRODUCTION SCHEDULE WOULD RETURN TO ITS CURRENT
CONFIGURATION.

IF YOU HAVE ANY QUESTIONS ABOUT THESE CHANGES TO THE NCEP GLOBAL
FORECAST SYSTEM PLEASE CONTACT:

    HUA-LU PAN
    NCEP/CAMP SPRINGS MARYLAND
    PHONE:  301-763-8000 EXT. 7234
    E-MAIL: HUALU.PAN@xxxxxxxx

    OR

    JOHN WARD
    NCEP/CAMP SPRINGS MARYLAND
    PHONE: 301-763-8000 EXT. 7185
    E-MAIL: JOHN.WARD@xxxxxxxx

THIS AND OTHER NWS TECHNICAL IMPLEMENTATION NOTICES ARE AVAILABLE
ON THE INTERNET AT /USE LOWER CASE/:

    HTTP://WWW.NWS.NOAA.GOV/OM/NOTIF.HTM

$$
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