NOUS41 KWBC 011310 AAA  
PNSWSH

TECHNICAL IMPLEMENTATION NOTICE 10-13 AMENDED
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
910 AM EDT THU APRIL 1 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:  AMENDED DATE: GLOBAL MULTI-GRID WAVE MODEL CHANGES:     
          POSTPONED UNTIL MAY 11 2010

AMENDED TO POSTPONE EFFECTIVE DATE FOR IMPLEMENTATION OF THE 
GLOBAL MULTI-GRID WAVE MODEL CHANGES FROM APRIL 27 2010 TO 
MAY 11 2010.

EFFECTIVE TUESDAY MAY 11 2010...BEGINNING WITH THE 1200 
COORDINATED UNIVERSAL TIME /UTC/ RUN...THE NATIONAL CENTERS 
FOR ENVIRONMENTAL PREDICTION /NCEP/ WILL UPGRADE THE GLOBAL 
MULTI-GRID WAVE MODEL. THE PRIMARY MODIFICATION WILL BE TO 
CHANGE THE ISSUANCE TIME OF THE MULTI-GRID WAVE MODEL GRIB2 
PRODUCTS DISSEMINATED VIA NOAAPORT...AWIPS...THE NCEP FTP 
SERVER AND NCEP’S REAL-TIME NOMADS SERVER. MODEL PRODUCTS FOR 
ALL PROJECTIONS ARE CURRENTLY DISSEMINATED AT APPROXIMATELY 
4 HOURS 30 MINUTES AFTER MODEL CYCLE TIME...WITH ALL 
PROJECTIONS AVAILABLE IN ONE OUTPUT FILE PER MODEL GRID. 

STARTING ON MAY 11...THE GRIB2 PRODUCTS WILL BE DISSEMINATED 
THROUGHOUT THE RUN OF THE MODEL AS EACH FORECAST HOUR 
COMPLETES. PRODUCTS WILL BEGIN TO BE DISSEMINATED AT 
APPROXIMATELY 3 HOURS 30 MINUTES AFTER MODEL CYCLE TIME WITH 
THE LAST FORECAST PROJECTION DISSEMINATED AT 4 HOURS 30 
MINUTES AFTER MODEL CYCLE TIME. ON THE FTP SERVERS AND 
NOMADS...EACH FORECAST HOUR WILL NOW BE PROVIDED IN A 
SEPARATE FILE FOR EACH MODEL GRID.  

THERE WILL BE NO CHANGE IN DISSEMINATION TIME FOR THE POINT-
BASED OUTPUT PRODUCTS DISSEMINATED VIA NOAAPORT AND AWIPS.  
THOSE PRODUCTS WILL CONTINUE TO BE DISSEMINATED AT 4 HOURS 
30 MINUTES AFTER MODEL CYCLE TIME.

ADDITIONAL CHANGES TO THE MULTI-GRID WAVE MODEL INCLUDE:

-INCREASE THE SPECTRAL RESOLUTION OF THE MODEL TO 50 BINS IN 
FREQUENCY AND 36 BINS IN DIRECTION. THIS RESOLUTION CHANGE 
ONLY AFFECTS THE INTERNAL COMPUTATIONS OF THE MODEL. NO 
OUTPUT PRODUCTS WILL CHANGE RESOLUTION.

-EXTEND THE WAVE DATA COVERAGE ON THE GLOBAL GRID FROM 77.5N 
TO 82.5N. THE GLOBAL OUTPUT GRID WILL REMAIN THE SAME. THE 
NUMBER OF POINTS ON THAT GRID WITH NON-MISSING DATA VALUES 
WILL INCREASE. A VERY SMALL INCREASE IN DATA VOLUME IS 
EXPECTED DUE TO THIS CHANGE.

-CHANGES WILL BE MADE TO ELIMINATE SMALL INSTABILITIES IN THE 
CORNER OF THE COASTAL PACIFIC GRID /WC_4M/.

MORE DETAILS ABOUT THE NCEP MULTI-GRID WAVE MODEL ARE 
AVAILABLE AT /USE LOWERCASE/:

  HTTP://POLAR.NCEP.NOAA.GOV/WAVES/INDEX2.SHTML

A CONSISTENT PARALLEL FEED OF DATA IS AVAILABLE ON THE NCEP 
FTP SERVER FROM THE PARALLEL MODEL RUNNING ON THE NCEP 
CENTRAL COMPUTING SYSTEM.  THE PARALLEL DATA IS AVAILABLE VIA 
THE FOLLOWING URL /USE LOWERCASE/:

  FTP://FTP.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/WAVE/PARA

NCEP ENCOURAGES ALL USERS TO ENSURE THEIR DECODERS ARE 
FLEXIBLE AND CAN HANDLE CHANGES IN CONTENT...PARAMETER FIELDS 
CHANGING ORDER...CHANGES IN THE SCALING FACTOR COMPONENT 
WITHIN THE PRODUCT DESCRIPTION SECTION /PDS/ OF THE GRIB 
FILES AND VOLUME CHANGES. THESE ELEMENTS MAY CHANGE WITH 
FUTURE NCEP MODEL IMPLEMENTATIONS. NCEP WILL MAKE EVERY 
ATTEMPT TO ALERT USERS TO THESE CHANGES PRIOR TO ANY 
IMPLEMENTATION.

FOR QUESTIONS REGARDING THESE MODEL CHANGES...PLEASE CONTACT: 

  HENDRIK TOLMAN
  NCEP/MARINE MODELING AND ANALYSIS BRANCH
  CAMP SPRINGS MARYLAND
  301-763-8000 X 7253
  HENDRIK.TOLMAN@NOAA.GOV

FOR QUESTIONS REGARDING THE DATAFLOW ASPECTS OF THESE DATA 
SETS... PLEASE CONTACT 

  REBECCA COSGROVE
  NCEP/NCO DATAFLOW TEAM
  CAMP SPRINGS MARYLAND 20746
  301-763-8000 X 7198 
  NCEP.LIST.PMB-DATAFLOW@NOAA.GOV


NWS NATIONAL TECHNICAL IMPLEMENTATION NOTICES ARE ONLINE AT 
/USE LOWERCASE/:

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

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