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TECHNICAL IMPLEMENTATION NOTICE 08-23  
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
1210 PM EDT THU MAR 20 2008

TO:       SUBSCRIBERS:
	  -FAMILY OF SERVICES
	  -NOAA WEATHER WIRE SERVICE
	  -EMERGENCY MANAGERS WEATHER INFORMATION NETWORK 
	  OTHER NWS PARTNERS...USERS AND EMPLOYEES

FROM:     JASON TUELL
          CHIEF...SCIENCE PLANS BRANCH
          OFFICE OF SCIENCE AND TECHNOLOGY /OST/

SUBJECT:  ADDITION OF NOAA WAVEWATCH III MODEL GRIDS TO 
          SBN/NOAAPORT: EFFECTIVE APRIL 29 2008

EFFECTIVE TUESDAY APRIL 29 2008...WITH THE 1200 COORDINATED 
UNIVERSAL TIME /UTC/ RUN...NEW WAVEWATCH III /NWW3/ MODEL GRIDS 
PRODUCED BY THE NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION 
/NCEP/ WILL BE ADDED TO THE NOAAPORT TG2 CHANNEL. THESE NEW GRIDS 
WILL BE DISSEMINATED IN GRIB2 FORMAT. THE LEGACY GRIB1 NWW3 GRIDS 
WILL CONTINUE TO BE AVAILABLE OVER NOAAPORT.

CHARACTERISTICS OF THE NEW GRIB2 GRIDS INCLUDE:

1. THE GRIDS HAVE INTERNAL TWO-WAY COUPLING AND EXCHANGE  
   INFORMATION DURING THE COMPUTATION CYCLE. THE NEW GRIDS ARE: 
   A.  A 30 MINUTE RESOLUTION GLOBAL GRID.  
   B.  THREE 10 MINUTE RESOLUTION REGIONAL GRIDS COVERING THE   
       UNITED STATES /US/...EAST/WEST COASTS AND EASTERN   
       PACIFIC ISLANDS INCLUDING HAWAII.  
   C.  AN ALASKA REGIONAL GRID WITH A 15 MINUTE RESOLUTION IN    
       LONGITUDE AND A 10 MINUTE RESOLUTION IN LATITUDE.  
   D.  TWO 4 MINUTE RESOLUTION COASTAL GRIDS FOR THE US 
       EAST/WEST COASTS. THE US WEST COAST GRID ALSO 
       INCLUDES THE COASTAL WATERS OF THE HAWAIIAN ISLANDS.
   E.  AN ALASKAN COASTAL GRID WITH A RESOLUTION OF 8 MINUTES  
       IN LONGITUDE AND 4 MINUTES IN LATITUDE. 

2. DOMAIN OF THE GLOBAL GRID IS EXTENDED FROM 78 N TO 90 N.  FOR  
   NOW THE DATA IN THE ADDITIONAL GRID POINTS WILL BE MARKED AS  
   UNDEFINED. THE GRID POINTS WILL BE POPULATED WITH DATA IN A 
   LATER NWW3 UPDATE.

3. THE ENERGY SPECTRUM IS NOW PROPERLY PARTITIONED. ASSOCIATED
   WITH THIS ARE ADDITIONAL OUTPUT FIELDS IN THE GRIB FILES
   INCLUDING:
   A.  PARTITIONED WAVE HEIGHT DATA FOR WIND SEAS...PRIMARY 
       SWELLS AND SECONDARY SWELLS.
   B.  PARTITIONED PEAK PERIOD DATA FROM WIND SEAS...PRIMARY 
       SWELLS AND SECONDARY SWELLS.
   C.  PARTITIONED MEAN DIRECTION FOR WIND SEAS...PRIMARY  
       SWELLS AND SECONDARY SWELLS.

       THESE NEW FIELDS REPLACE THE EARLIER MEAN WAVE PERIOD 
       ...MEAN WAVE DIRECTION...PEAK FREQUENCY...PEAK 
       DIRECTION AND WIND SEA PEAK FREQUENCY AND WIND SEA  
       DIRECTION.     

4.  THE MODEL PHYSICS INCLUDES A LINEAR WAVE GROWTH TERM TO  
    IMPROVE INITIAL WAVE GROWTH RESULTS AND A SURF ZONE BREAKING 
    TERM TO PROVIDE MORE REALISTIC ESTIMATES OF WAVE HEIGHTS FOR 
    LANDFALLING HURRICANES.

5.  THE FORECAST INTERVAL FOR 0 TO 72 HOURS WILL BE 3 HOURS.  
    FORECAST INTERVAL FROM 72 TO 180 HOURS WILL BE 6 HOURS.  

THERE WILL BE 4 MODEL DISTRIBUTIONS DAILY CORRESPONDING TO THE 
0000...0600...1200 AND 1800 UTC MODEL RUN. THE TIMING OF THE 
DELIVERY ON NOAAPORT WILL BE APPROXIMATELY FIVE HOURS AFTER THE 
FOUR MODEL RUN TIMES.

THE PER CYCLE DATA VOLUME WILL BE APPROXIMATELY 275 MEGABYTES 
/MB/ OR APPROXIMATELY 1.1 GIGABYTES /GB/ PER DAY.

THE WMO HEADINGS FOR THESE PRODUCTS WILL BE OF THE FORM:

   T1:     DATA FORMAT OF GRIB2 /E/
   T2:     PARAMETER CODE /ONE OF ABCJKLMNOPQRY/
   A1:     GRID CODE /ONE OF ABCDEFGH/ 
   A2:     FORECAST TIME /ONE OF ABCDEFGHIJKLMNOPQRSTUVWXYZ/
   II:     LAYER OR LEVEL /88/
   CCCC:   KWBJ    

A COMPLETE DESCRIPTION AND LIST OF WMO HEADINGS IS ONLINE AT  
/USE LOWER CASE LETTERS/:

HTTP://WWW.WEATHER.GOV/OS/NOTIFICATION/RESOURCES/WMO_HEADINGS.PDF

FOR QUESTIONS RELATED TO MODEL CHANGES...PLEASE CONTACT: 

     HENDRIK TOLMAN
     NCEP/EMC...CHIEF MARINE MODELING BRANCH
     CAMP SPRINGS MARYLAND
     PHONE: 301 763 8000 X7253
     EMAIL: HENDRIK.TOLMAN@NOAA.GOV

FOR QUESTIONS ABOUT NOAAPORT ACTIVATION...PLEASE CONTACT:

     JOHN F. KUHN
     NWS OFFICE OF SCIENCE AND TECHNOLOGY
     SILVER SPRING MARYLAND
     PHONE: 301 713 3557 X184  
     EMAIL: JOHN.F.KUHN@NOAA.GOV

NWS TECHNICAL IMPLEMENTATION NOTICES ARE ONLINE AT  
/USE LOWER CASE LETTERS/: 

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

$$
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