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-------- Original Message --------986 NOUS41 KWBC 021253
PNSWSH TECHNICAL IMPLEMENTATION NOTICE 10-15 NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC 853 AM EDT FRI APR 2 2010 TO: SUBSCRIBERS:-FAMILY OF SERVICES -NOAA WEATHER WIRE SERVICE
-EMERGENCY MANAGERS WEATHER INFORMATION NETWORK
-NOAAPORT
OTHER NWS PARTNERS...USERS AND EMPLOYEES
FROM: TIMOTHY MCCLUNG
SCIENCE PLANS BRANCH CHIEF
OFFICE OF SCIENCE AND TECHNOLOGY
SUBJECT: GLOBAL FORECAST SYSTEM CHANGES:
EFFECTIVE JUNE 22 2010.
EFFECTIVE JUNE 22 2010...BEGINNING WITH THE 1200 COORDINATED UNIVERSAL TIME /UTC/ RUN...THE NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION /NCEP/ WILL UPGRADE THE GLOBAL FORECAST SYSTEM /GFS/. THE RESOLUTION OF THE GLOBAL FORECAST MODEL WILL BE INCREASED FROM T382 /35 KM/ TO T574 /27 KM/. THE HIGH RESOLUTION PORTION OF THE FORECAST WILL BE EXTENDED FROM 180 HRS TO 192 HRS. WITH THIS EXTENSION 3 HOURLY OUTPUT WILL BE MADE AVAILABLE OUT TO 192 HOURS. THIS WILL RESULT IN SIGNIFICANT CHANGES IN THE DEFINITION OF PARAMETERS IN THE 192 HOUR PRESSURE GRIB /PGRB/ AND FLUX FILES. THERE WILL ALSO BE SIGNIFICANT CHANGES IN MODEL PHYSICS ASSOCIATED WITH THIS CHANGE. IN ADDITION MODIFICATIONS WILL BE MADE TO THE CONTENTS OF THE GLOBAL DATA ASSIMILATION SYSTEM /GDAS/ AND GFS PGRB FILES.
CHANGES IN MODEL PHYSICS INCLUDE:RADIATION AND CLOUD OVERLAP GRAVITY WAVE DRAG
HURRICANE RELOCATION NEW PLANETARY BOUNDARY LAYER SCHEME NEW MASS FLUX SHALLOW CONVECTION UPDATED DEEP CONVECTION SCHEME POSITIVE DEFINITE TRACER TRANSPORT SCHEMETHE NEW PARAMETER FOR THE GFS FORECAST PRESSURE GRIB FILES IS: MAX WIND GUST
SEVERAL PARAMETERS ARE BEING DELETED FROM THE GDAS ANALYSIS PRESSURE GRIB FILES BECAUSE THEY ARE NOT VALID FOR THE ANALYSIS DATASET AND HAVE NEVER PROVIDED PERTINENT INFORMATION. THESE INCLUDE: 4 PRECIPITATION TYPES
CONVECTIVE PRECIPITATION RATE LAND SEA MASKLATENT HEAT FLUX SENSIBLE HEAT FLUX
PRECIPITATION RATE 2M RH 2M SPECIFIC HUMIDITY 2M TEMPERATURE BOUNDARY LAYER CLOUD COVERLOW CLOUD COVER CONVECTIVE CLOUD COVER
SKIN TEMPERATURE SURFACE UPWARD LONG WAVE FLUX SURFACE UPWARD SHORT WAVE FLUX HELICITYTHESE PARAMETERS ARE BEING DELETED FROM THE GLOBAL FORECAST MODEL SIMULATED GOES GRIB FILE BECAUSE THEY WERE INCLUDED IN ERROR. THESE FIELDS ARE AVAILABLE IN THE PGRB FILES:
MEAN SEA LEVEL PRESSURE WAVE-5 GEOPOTENTIAL HEIGHTALL ACCUMULATED OR AVERAGED VALUES IN THE 192 HOUR PGRB AND FLUX FILES WILL NOW BE OVER A 6 HOUR PERIOD INSTEAD OF 12 HOURS. THE FORMAT AND CONTENT OF THE 3 HOURLY FILES FROM 180 TO 192 HOURS WILL BE THE SAME AS THE FILES FROM 0 TO 180. FOR THE FLUX FILE...THIS INCLUDES THE MAJORITY OF THE PARAMETERS IN THE FILE. PARAMETERS CHANGING IN THE PGRB FILE ARE: 2 M ABOVE GROUND MAX. TEMPERATURE 2 M ABOVE GROUND MIN. TEMPERATURE SURFACE ALBEDO SURFACE CLEAR SKY UV-B DOWNWARD SOLAR FLUX SURFACE CATEGORICAL FREEZING RAIN SURFACE CATEGORICAL ICE PELLETS SURFACE CONVECTIVE PRECIPITATION RATE SURFACE CATEGORICAL RAIN SURFACE CATEGORICAL SNOW ATMOSPHERIC COLUMN CLOUD WORK FUNCTION SURFACE DOWNWARD LONG WAVE FLUX SURFACE DOWNWARD SHORT WAVE FLUX SURFACE UV-B DOWNWARD SOLAR FLUX SURFACE GROUND HEAT FLUX SURFACE LATENT HEAT FLUX SURFACE PRECIPITATION RATE LOW CLOUD BASE PRESSURE LOW CLOUD TOP PRESSURE MID-CLOUD BASE PRESSURE MID-CLOUD TOP PRESSURE HIGH CLOUD BASE PRESSURE HIGH CLOUD TOP PRESSURE SURFACE SENSIBLE HEAT FLUX ATMOSPHERIC COLUMN TOTAL CLOUD COVER BOUNDARY CLOUD LAYER TOTAL CLOUD COVER LOW CLOUD COVER MID-CLOUD COVER HIGH CLOUD COVER LOW CLOUD TOP TEMPERATURE MID-CLOUD TOP TEMPERATURE HIGH CLOUD TOP TEMPERATURE SURFACE ZONAL GRAVITY WAVE STRESS SURFACE ZONAL MOMENTUM FLUX SURFACE UPWARD LONG WAVE FLUX TOP OF ATMOSPHERE UPWARD LONG WAVE FLUX SURFACE UPWARD SHORT WAVE FLUX TOP OF ATMOSPHERE UPWARD SHORT WAVE FLUX SURFACE MERIDIONAL GRAVITY WAVE STRESS
SURFACE MERIDIONAL MOMENTUM FLUXSURFACE CONVECTIVE PRECIPITATION SURFACE TOTAL PRECIPITATION SURFACE LARGE SCALE PRECIPITATION
NOTE THAT FOR THE 192 HR PGRB PRODUCTS AVAILABLE ON NOAAPORT AND IN AWIPS THE ACCUMULATIONS AND AVERAGES WILL REMAIN OVER THE PREVIOUS 12 HOUR PERIOD UNTIL AWIPS IS MODIFIED TO ACCOMMODATE THIS CHANGE.
THE FORMAT OF THE HALF AND ONE DEGREE PRESSURE GRIB FILES WILL REMAIN THE SAME EXCEPT FOR THE CHANGES IN VARIABLES LISTED ABOVE. THE SIZE OF THESE FILES WILL NOT CHANGE SIGNIFICANTLY. WITH THE INCREASE IN MODEL RESOLUTION... THE SIZE OF THE SIGMA COEFFICIENT FILES AND THE SURFACE FLUX FILES WILL INCREASE SIGNIFICANTLY.
THESE CONTENT CHANGES WILL IMPACT ALL DISSEMINATION ROUTES: NWS PUBLIC FTP SERVER...THE NCEP PUBLIC FTP SERVER...AND NOAAPORT. A SET OF TEST DATA IS AVAILABLE AT /USE LOWERCASE/ EXCEPT FOR GFS AND T574L64:
FTP.EMC.NCEP.NOAA.GOV/GC_WMB/WX24FY/GFS_T574L64/GFS.20091217A CONSISTENT PARALLEL FEED OF DATA WILL BECOME AVAILABLE ON THE NCEP FTP SERVER ONCE THE MODEL IS RUNNING IN PARALLEL ON THE NCEP CENTRAL COMPUTING SYSTEM IN MID APRIL. AT THAT TIME THE PARALLEL DATA WILL BECOME AVAILABLE VIA THE FOLLOWING URL /USE LOWERCASE/:
FTP://FTP.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PARADATA DELIVERY TIMING OF THE GFS WILL NOT BE IMPACTED BY THIS IMPLEMENTATION. NCEP ENCOURAGES ALL USERS TO ENSURE THEIR DECODERS ARE FLEXIBLE AND ARE ABLE OF ADEQUATELY HANDLING CHANGES IN CONTENT...PARAMETER FIELDS CHANGING ORDER...CHANGES IN THE SCALING FACTOR COMPONENT WITHIN THE PRODUCT DEFINITION SECTION /PDS/ OF THE GRIB FILES AND ANY VOLUME CHANGES WHICH MAY OCCUR. THESE ELEMENTS MAY CHANGE WITH FUTURE NCEP MODEL IMPLEMENTATIONS. NCEP WILL MAKE EVERY ATTEMPT TO ALERT USERS TO THESE CHANGES PRIOR TO ANY IMPLEMENTATIONS.
IF YOU HAVE ANY QUESTIONS CONCERNING THESE CHANGES...PLEASE CONTACT:
JOHN H. WARD NCEP...GLOBAL MODELING BRANCH CAMP SPRINGS MARYLAND PHONE: 301-763-8000 X7185 EMAIL: JOHN.WARD@xxxxxxxx OR SHRINIVAS MOORTHI NCEP...GLOBAL MODELING BRANCH CAMP SPRINGS MARYLAND PHONE: 301-763-8000 X7233 EMAIL: SHRINIVAS.MOORTHI@xxxxxxxxNWS NATIONAL TECHNICAL IMPLEMENTATION NOTICES ARE ONLINE AT /USE LOWERCASE/:
HTTP://WWW.WEATHER.GOV/OS/NOTIF.HTM
$$ NNNN
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