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TECHNICAL IMPLEMENTATION NOTICE 07-90 CORRECTED
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
405 PM EDT TUE MAR 11 2008

TO:       FAMILY OF SERVICES /FOS/ SUBSCRIBERS
          NOAAPORT SUBSCRIBERS
          OTHER NWS PARTNERS
          OTHER USERS AND NWS EMPLOYEES

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

SUBJECT:  CORRECTED: ADDITION OF NCEP RTMA GRIDS FOR THE ALASKA    
          REGION: EFFECTIVE MARCH 13 2008 

REFER TO: TECHNICAL IMPLEMENTATION NOTICE /TIN/ 07-90 TRANSMITTED
          ON NOVEMBER 13 2007

CORRECTED TO ADD FEEDBACK LINK AT BOTTOM OF THIS NOTICE.

AMENDED TO DELAY THE IMPLEMENTATION DATE OF REAL TIME MESOSCALE 
ANALYSIS /RTMA/ ADDITION TO THE NATIONAL DIGITAL GUIDANCE 
DATABASE /NDGD/ FROM JANUARY 22 2008 TO MARCH 13 2008. ADDITION 
OF RTMA TO NOAAPORT PROCEEDED ON JANUARY 24 2008.

EFFECTIVE THURSDAY MARCH 13 2008...AT APPROXIMATELY 1500 
COORDINATED UNIVERSAL TIME /UTC/...THE NATIONAL CENTERS FOR 
ENVIRONMENTAL PREDICTION /NCEP/ WILL BEGIN DISSEMINATING RTMA FOR 
THE ALASKA REGION VIA NDGD.

RTMA FOR ALASKA CONSISTS OF A SET OF GRIDDED SURFACE ANALYSES 
CORRESPONDING TO THE 10 PARAMETERS LISTED BELOW IN TABLE 1.  
SIMILAR TO THE CONUS RTMA PRODUCTS ALREADY PROVIDED VIA NOAAPORT 
AND NDGD...THESE NEW ALASKA REGION GRIDS ARE ALSO INTENDED FOR 
DISTRIBUTION IN NEAR REAL TIME. THUS IN THE GENERATION OF THESE 
GRIDS...NCEP INGESTS AS MUCH SATELLITE...RADAR...ASOS... MESONET 
...AND OTHER SENSOR DATA AS IT CAN ACQUIRE IN NEAR REAL TIME. THE 
SENSOR DATA ARE ANALYZED AND INTERPOLATED TO A 6 KM RESOLUTION 
ALASKA REGION POLAR STEREOGRAPHIC GRID AND ENCODED IN GRIB2.  

NCEP GENERATES ONE SET OF ALASKA REGION RTMA GRIDS EACH HOUR.  
EACH HOURLY GRID HAS A VALID TIME CORRESPONDING TO AN 
EVEN HOUR /I.E. 0000...0100...0200...THRU 2300/. THE ALASKA RTMA 
GRIDS WILL BECOME AVAILABLE ON NDGD AT APPROXIMATELY 45 MINUTES 
AFTER THE VALID TIME HOUR.

THE HOURLY DATA VOLUME IS APPROXIMATELY 6 MEGABYTES /MB/.  
THE DAILY DATA VOLUME IS APPROXIMATELY 144 MB.

ALL OF THE GRIDS LISTED IN TABLE 1 ARE ALREADY CARRIED ON 
NOAAPORT.

TABLE 1:  WMO HEADINGS ASSIGNED TO THE ALASKA REGION RTMA GRIDS

WMO HEADING  RTMA PARAMETERS

LTAA98 KWBR: TEMPERATURE ANALYSIS
LTAA98 KWBR: TEMPERATURE ANALYSIS UNCERTAINTY
LRAA98 KWBR: DEWPOINT TEMPERATURE ANALYSIS
LRAA98 KWBR: DEWPOINT TEMPERATURE ANALYSIS UNCERTAINTY
LNAA98 KWBR: WIND SPEED ANALYSIS
LNAA98 KWBR: WIND SPEED ANALYSIS UNCERTAINTY
LNAA98 KWBR: WIND DIRECTION ANALYSIS
LNAA98 KWBR: WIND DIRECTION ANALYSIS UNCERTAINTY
LUAA98 KWBR: U WIND COMPONENT ANALYSIS /NOAAPORT ONLY/
LVAA98 KWBR: V WIND COMPONENT ANALYSIS /NOAAPORT ONLY/

ALL OF THE GRIDS LISTED IN TABLE 1 ARE ALREADY FLOWING ON 
NOAAPORT.  ALL OF THE GRIDS LISTED IN TABLE 1...EXCEPT FOR U AND 
V WINDS...WILL BECOME AVAILABLE IN NDGD ON MARCH 13 2008. THE 
GRIDS WILL BE IN GRIB2 FORMAT IN SUBDIRECTORIES OF /USE LOWER 
CASE LETTERS EXCEPT FOR SL...ST...DF...DC...GT...AND AR/:

FTP://TGFTP.NWS.NOAA.GOV/SL.US008001/ST.EXPR/DF.GR2/DC.NDGD/GT.RT
MA/AR.ALASKA

HTTP://WEATHER.NOAA.GOV/PUB/SL.US008001/ST.EXPR/DF.GR2/DC.NDGD/GT
.RTMA/AR.ALASKA/

THERE ARE 24 SUBDIRECTORIES BENEATH THE AR.ALASKA DIRECTORY 
...ONE FOR EACH HOUR OF THE DAY: RT.00...RT.01...RT.02...THROUGH 
RT.23. EACH HOURLY SUBDIRECTORY WILL STORE THE RTMA FILES FOR 
THAT NOMINAL HOUR. THE RTMA FILES IN EACH HOURLY SUBDIRECTORY 
WILL BE NAMED AS SHOWN IN TABLE 2 /USE LOWER CASE LETTERS FOR ALL 
FILE NAMES/:

TABLE 2:  NDGD FILE NAMES FOR ALASKA REGION RTMA GRIDS

FILE NAME       RTMA PARAMETER

DS.TEMP.BIN     TEMPERATURE ANALYSIS
DS.UTEMP.BIN    TEMPERATURE ANALYSIS UNCERTAINTY
DS.TD.BIN       DEWPOINT TEMPERATURE ANALYSIS
DS.UTD.BIN      DEWPOINT TEMPERATURE ANALYSIS UNCERTAINTY
DS.WSPD.BIN     WIND SPEED ANALYSIS
DS.UWSPD.BIN    WIND SPEED ANALYSIS UNCERTAINTY
DS.WDIR.BIN     WIND DIRECTION ANALYSIS
DS.UWDIR.BIN    WIND DIRECTION ANALYSIS UNCERTAINTY

THE RESIDENCE TIME OF NDGD RTMA FILES WILL BE APPROXIMATELY ONE 
DAY. EACH HOUR NEW FILES WILL BE WRITTEN TO THE MOST RECENT 
HOURLY DIRECTORY...OVERWRITING THE FILES CORRESPONDING TO THE 
SAME HOUR ON THE PREVIOUS DAY.  

NCEP HAS CREATED THE FOLLOWING WEB SITE FOR PREVIEWING UP-TO-DATE 
ALASKA RTMA /USE LOWER CASE/:

HTTP://WWW.EMC.NCEP.NOAA.GOV/MMB/RTMA/ALASKA/ 

FOR QUESTIONS ABOUT THE TECHNICAL CONTENT OR GENERATION OF THESE 
PRODUCTS...PLEASE CONTACT: 

         GEOFF DIMEGO 
         NWS NCEP ENVIRONMENTAL MODELING CENTER 
         CAMP SPRINGS MARYLAND
         PHONE: 301 763 8000 EXT 7221 
         EMAIL: GEOFF.DIMEGO@NOAA.GOV

FOR QUESTIONS ABOUT THE NCEP DATAFLOW ASPECTS OF THESE DATA SETS 
...WRITE THE NCEP/NCO/PMB DATAFLOW HELP DESK EMAIL ADDRESS BELOW.

         EMAIL: NCEP.PMB.DATAFLOW@NOAA.GOV

FOR QUESTIONS CONCERNING THE NDGD ACTIVATION OF THESE 
PRODUCTS...PLEASE CONTACT:  
 
         BRIAN GOCKEL  
         NWS OFFICE OF SCIENCE AND TECHNOLOGY  
         SILVER SPRING MARYLAND 
         PHONE: 301 713 0304 EXT 158 
         EMAIL: BRIAN.GOCKEL@NOAA.GOV

USERS CAN PROVIDE FEEDBACK ABOUT THE ALASKA RTMA AT THE FOLLOWING 
WEB SITE:
 
  HTTP://WWW.WEATHER.GOV/SURVEY/NWS-SURVEY.PHP?CODE=RTMA-AK

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

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

$$
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