ADMIN NOTICE NOUS41 KWBC (fwd)

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: ADMIN NOTICE NOUS41 KWBC (fwd)
• From: Jeff Weber <jweber@xxxxxxxxxxxxxxxx>
• Date: Fri, 12 Jul 2002 12:59:08 -0600 (MDT)

616 
NOUS41 KWBC 121710
PNSWSH

PUBLIC INFORMATION STATEMENT...TECHNICAL INFORMATION NOTICE 02-12
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
110 PM EDT FRI JUL 12 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/

SUBJECT:  CHANGES TO THE HORIZONTAL AND VERTICAL RESOLUTIONS OF
          THE NCEP GLOBAL FORECAST SYSTEM...EFFECTIVE AUG 13 2002
          AT 1200 UTC

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

ON AUGUST 13 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 21 MINUTES
     WAVE MODEL PRODUCTS DELAYED 19 MINUTES
     AVN MOS PRODUCTS DELAYED 21 MINUTES
     1200 UTC GLOBAL ENSEMBLE PRODUCTS DELAYED 28 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
     PHONE:  301-763-8000 EXT. 7234
     E-MAIL: HUALU.PAN@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
  
END

-Jeff
____________________________                  _____________________
Jeff Weber                                    jweber@xxxxxxxx
Unidata Support                               PH:303-497-8676
NWS-COMET Case Study Library                  FX:303-497-8690
University Corp for Atmospheric Research      3300 Mitchell Ln
http://www.unidata.ucar.edu/staff/jweber      Boulder,Co 80307-3000
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