Posted: Mon, Dec 6, 1993 2:12 PM EST Msg: EGJD-6007-1101
Subj: NTIM on Interactive Satellite Retrievals
WSHPNSNMC
NOUS41 KWBC 061900
NATIONAL TECHNICAL INFORMATION MESSAGE 93-45
NATIONAL WEATHER SERVICE HEADQUARTERS
200 PM EST MON DEC 6 1993
TO: ALL USERS OF NATIONAL METEOROLOGICAL CENTER (NMC)
PRODUCTS
FROM: JOHN F. MACHOWSKI
ACTING CHIEF, SERVICES DEVELOPMENT BRANCH
SUBJECT: IMPLEMENTATION OF INTERACTIVE SATELLITE TEMPERATURE
RETRIEVALS INTO THE GLOBAL FORECAST SYSTEM
(THE FOLLOWING INFORMATION WAS PROVIDED BY WAYMAN BAKER, DEPUTY
CHIEF OF NMC'S DEVELOPMENT DIVISION).
AT 1200 UTC ON DECEMBER 7, 1993, A CHANGE WILL BE MADE IN THE
WAY SATELLITE TEMPERATURE RETRIEVALS ARE PRODUCED FOR USE IN THE
NMC AVIATION AND MEDIUM RANGE FORECAST SYSTEM OVER THE NORTHERN
HEMISPHERE. THE NEW APPROACH, REFERRED TO AS "INTERACTIVE", HAS
BEEN JOINTLY DEVELOPED BY THE NMC DEVELOPMENT DIVISION AND THE
NESDIS OFFICE OF RESEARCH AND APPLICATIONS.
THE INTERACTIVE RETRIEVALS ARE PRODUCED USING THE 6 HOUR
FORECAST FROM THE NMC GLOBAL DATA ASSIMILATION SYSTEM AS THE
"FIRST GUESS" FOR THE TEMPERATURE RETRIEVAL GENERATION. THE
MODEL 6 HOUR FORECAST (FIRST GUESS) RESULTS IN A MORE ACCURATE
SET OF RETRIEVALS, WHICH IN TURN GENERALLY CONTRIBUTES TO AN
IMPROVED FORECAST.
WITH THE IMPLEMENTATION OF THE INTERACTIVE RETRIEVALS, A
SMALL IMPROVEMENT MAY BE EXPECTED, ON THE AVERAGE, IN THE
FORECASTS BEYOND 72 HOURS THROUGHOUT THE TROPOSPHERE AND LOWER
STRATOSPHERE OVER THE NORTHERN HEMISPHERE. AFTER CONVERSION OF
THE GLOBAL FORECAST SYSTEM TO THE NMC CLASS VII COMPUTER IN
EARLY 1994, FURTHER TESTS OF THE INTERACTIVE RETRIEVALS WILL BE
PERFORMED IN ORDER TO FINALIZE THE SCHEME FOR USE IN THE SOUTHERN
HEMISPHERE.
QUESTIONS REGARDING THIS CHANGE MAY BE DIRECTED TO STEPHEN LORD
OF NMC'S DEVELOPMENT DIVISION WHO CAN BE REACHED AT 301-763-8005.
END - SENT - W/OM23