20060724: GFS changes

426 NOUS41 KWBC 241816 
PNSWSH

TECHNICAL IMPLEMENTATION NOTICE 06-44...CORRECTED
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
215 PM EDT MON JUL 24 2006
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:     PAUL HIRSCHBERG
         CHIEF...SCIENCE PLANS BRANCH
         OFFICE OF SCIENCE AND TECHNOLOGY /OST/
SUBJECT: CORRECTED: UPGRADES TO THE NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION GLOBAL FORECAST SYSTEM POSTPONED UNTIL AUGUST 22 2006. 

REFER TO: TECHNICAL IMPLEMENTATION NOTICE /TIN/ 06-44
  TRANSMITTED ON JUNE 20 2006 AND TIN 06-44 /AMENDED/
         TRANSMITTED ON JULY 21 2006
CORRECTED TO DELETE REFERENCE IN THE AMENDED TIN 06-44 TO THE HYBRID COORDINATE SYSTEM BEING PART OF THE GFS UPGRADE PACKAGE.
THE TEXT OF THE ORIGINAL AMENDED TIN...MINUS INFORMATION ON THE HYBRID COORDINATE CHANGE...IS GIVEN BELOW.
THIS NOTICE AMENDS TIN 06-44 TO DELAY THE IMPLEMENTATION DATE OF THIS UPGRADE FROM JULY 25 2006 TO AUGUST 22 2006. IN ADDITION THE ORIGINAL NOTICE INDICATED THAT THE NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION /NCEP/ WOULD BE SWITCHING THE GLOBAL FORECAST SYSTEM /GFS/ TO USE A HYBRID COORDINATE SYSTEM FOR ITS PROCESSING. THIS CHANGE HAS BEEN REMOVED FROM THE UPGRADE PACKAGE. THE GFS WILL CONTINUE TO BE PRODUCED IN THE PRESSURE COORDINATE SYSTEM.
THE ORIGINAL NOTICE...MINUS INFORMATION ON THE HYBRID COORDINATE CHANGE...IS GIVEN BELOW.
ON THE ABOVE EFFECTIVE DATE...BEGINNING WITH THE 1200 COORDINATED UNIVERSAL TIME /UTC/ RUN...THE NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION /NCEP/ WILL IMPLEMENT UPGRADES TO ITS GLOBAL FORECAST SYSTEM /GFS/ MODEL. THESE UPGRADES ARE AS FOLLOWS: 

    - ADDITION OF NAVAL RESEARCH LABORATORY /NRL/ OZONE
      PHYSICS
- ADDITION OF GLACIAL ICE PHYSICS WITH MODIFIED OROGRAPHY 
    - IMPROVED GLOBAL SNOW ANALYSIS /LESS INTERPOLATION/
    - CORRECTION TO SURFACE DOWNWARD LONGWAVE RADIATION,
    - CHANGE OF THE TIME-FILTER COEFFICIENT /0.85/
    - UPGRADES TO SURFACE CYCLING...COMPATIBLE WITH THE NEW
      SNOW ANALYSIS
    - USES EARTH SYSTEM MODELING FRAMEWORK /ESMF/
      SUPERSTRUCTURE
    - RESTART FILES ARE IN FULL PRECISION /FORECASTS ARE
      THUS REPRODUCIBLE/
    - WILL ALLOW MULTIPLE ENSEMBLE MEMBER FORECASTS TO BE
      RUN CONCURRENTLY

THE PURPOSE OF THESE CHANGES IS TO:

    - USE ESMF
    - MAKE MINOR IMPROVEMENTS /TIME FILTER COEFFICIENT AND
DOWNWARD LONGWAVE RADIATION/ - MAKE UPGRADES THAT HAVE BEEN PLANNED FOR A WHILE /NEW SNOW ANALYSIS/ 
    - MAKE PHYSICS CHANGES /OZONE, GLACIAL ICE/.
THE EXPECTED IMPACTS ARE GENERALLY MINOR...THOUGH ULTRAVIOLET /UV/ FORECASTS SHOULD BE IMPROVED BY THE CHANGED OZONE SCHEME.
THE NCEP ENVIRONMENTAL MODELING CENTER /EMC/ BEGAN RUNNING PARALLEL FORECASTS ON MAY 9 2006 AND IS CURRENTLY UP TO REAL TIME. STATISTICAL SCORE COMPARISONS FOR BOTH THE OPERATIONAL AND NEW GFS ARE AVAILABLE AT THE FOLLOWING WEB SITES /USE LOWER CASE/: 

EMC.NCEP.NOAA.GOV/GC_WMB/WD20XW/HTML_DIE/INDEX_PRYO_NEW.HTML
EMC.NCEP.NOAA.GOV/GC_WMB/WD20XW/HTML_LINE/INDEX_PRYO_NEW.HTML
IF YOU HAVE QUESTIONS ABOUT THESE CHANGES...PLEASE CONTACT: 
MARK IREDELL
NCEP...GLOBAL MODELING BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301 763 8000 X7231
EMAIL: MARK.IREDELL@xxxxxxxx

OR

BRENT GORDON
NCEP...PRODUCTION MANAGEMENT BRANCH
CAMP SPRINGS MARYLAND
PHONE: 301 763 8000 X7193
EMAIL: BRENT.GORDON@xxxxxxxx
THIS AND OTHER NWS TECHNICAL IMPLEMENTATION NOTICES ARE AVAILABLE ONLINE AT /USE LOWER CASE LETTERS/: 

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

$$
NNNN

--
Linda Miller - lmiller@xxxxxxxxxxxxxxxx
Community Services, Unidata
University Corporation for Atmospheric Research
P.O. Box 3000
Boulder, CO 80307-3000
303-497-8646 fax: 303-497-8690 

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