980109: Change to modeling of atmospheric vertical diffusion

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: 980109: Change to modeling of atmospheric vertical diffusion
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Fri, 9 Jan 1998 13:23:47 -0700 (MST)

ZCZC WSHPNSNMC ALL
TTAA00 KWSH DDHHMM

NATIONAL TECHNICAL IMPLEMENTATION MESSAGES /NTIM/ 98-01 AND 98-02
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
245 PM EST FRI JAN 9 1998

TO:       FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA WEATHER
          WIRE SERVICE /NWWS/ SUBSCRIBERS...OTHER NATIONAL
          WEATHER SERVICE /NWS/ CUSTOMERS...NWS EMPLOYEES

FROM:     LEROY SPAYD...CHIEF...SCIENCE AND TRAINING CORE

SUBJECTS: MESSAGE 98-01: CHANGE TO VERTICAL DIFFUSION IN THE NCEP
          GLOBAL FORECAST SYSTEM...EFFECTIVE JAN 12 1998

          MESSAGE 98-02: USE OF TOVS LVEL 1-B RADIANCES IN THE
          NCEP GLOBAL ANALYSIS SYSTEM...EFFECTIVE JAN 13 1998

NTIM MESSAGE 98-01...

BEGINNING WITH THE 12Z GLOBAL MODEL RUN ON JAN 12 1998...A CHANGE
TO THE MODELING OF ATMOSPHERIC VERTICAL DIFFUSION WILL BE
IMPLEMENTED INTO THE GLOBAL FORECAST SYSTEM (BOTH AVN AND MRF
RUNS)...EVALUATION AT T126 RESOLUTION SHOWS THAT A FORECASTER
WILL SEE LITTLE DIFFERENCE IN MIDDLE TO HIGH LATITUDES...HOWEVER
THERE WILL BE AN IMPACT IN THE TROPICS WHERE A TENDENCY FOR
SPURIOUS TROPICAL SYSTEMS WILL BE REDUCED...RESULTS WILL BE
PUBLISHED IN A FUTURE TECHNICAL PROCEDURES BULLETIN...SOON TO BE
FOUND ON THE NCEP/EMC HOMEPAGE...
HTTP://NIC.FB4.NOAA.GOV:8080/RESEARCH/GLOBAL2.HTML  /LOWER CASE/
/CLICK ON "RECENT TPB'S"/


NTIM MESSAGE 98-02:

BEGINNING WITH THE 12Z GLOBAL MODEL RUN ON JAN 13 1998...TOVS
LEVEL 1-B RADIANCES WILL BE INTRODUCED DIRECTLY INTO THE GLOBAL
ANALYSIS SYSTEM...THESE RADIANCES DO NOT UNDERGO THE PRE-
PROCESSING APPLIED TO PREVIOUSLY-USED CLOUD-CLEARED
RADIANCES...RATHER...THE NEW SYSTEM ELIMINATES CLOUD-INFLUENCED
RADIANCES INTERNALLY...CAREFUL EVALUATION AT T126 RESOLUTION
SHOWS THAT A FORECASTER SHOULD SEE IMPROVEMENTS IN ANALYSES AND
FORECASTS THROUGHOUT THE SOUTHERN HEMISPHERE AND ABOVE 250 HPA
OVER THE ENTIRE GLOBE...RESULTS WILL BE PUBLISHED IN A FUTURE
TECHNICAL PROCEDURES BULLETIN...SOON TO BE AVAILABLE ON THE
NCEP/EMC HOMEPAGE...
HTTP://NIC.FB4.NOAA.GOV:8080/RESEARCH/GLOBAL2.HTML /LOWER CASE/ 
/CLICK ON "RECENT TPB'S"/

END
NNNN^Z