-------- Original Message --------
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NOUS41 KWBC 111740
PNSWSH
TECHNICAL IMPLEMENTATION NOTICE 10-13
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
1240 PM EST THU MAR 11 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 MULTI-GRID WAVE MODEL CHANGES:
EFFECTIVE APRIL 27 2010
EFFECTIVE TUESDAY APRIL 27 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 CHANGE IS TO THE ISSUANCE
TIME OF THE MULTI-GRID WAVE MODEL GRIB2 PRODUCTS DISSEMINATED
VIA NOAAPORT...AWIPS...THE NCEP FTP SERVER AND NCEPS 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 APRIL 27...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 ARE ABLE OF ADEQUATELY HANDLING CHANGES IN
CONTENT...PARAMETER FIELDS CHANGING ORDER...CHANGES IN THE
SCALING FACTOR COMPONENT WITHIN THE PRODUCT DESCRIPTION
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 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@xxxxxxxx
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@xxxxxxxx
NWS NATIONAL TECHNICAL IMPLEMENTATION NOTICES ARE ONLINE AT
/USE LOWERCASE/:
HTTP://WWW.WEATHER.GOV/OS/NOTIF.HTM
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