VAS GRADIENT WINDS INTRODUCED TO AVIATION MODEL AND GDAS ANALYSES

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: VAS GRADIENT WINDS INTRODUCED TO AVIATION MODEL AND GDAS ANALYSES
• From: General Support <support@xxxxxxxxxxxxxxxx>
• Date: Mon, 21 Mar 1994 08:52:59 -0700

NATIONAL TECHNICAL INFORMATION MESSAGE 94-05
NATIONAL WEATHER SERVICE HEADQUARTERS
345 PM EDT THU MAR 17 1994

TO:         ALL USERS OF NMC'S AVIATION MODEL AND GLOBAL DATA
            ASSIMILATION SYSTEM (GDAS) ANALYSES

FROM:       JOHN F. MACHOWSKI
            ACTING CHIEF, SERVICES DEVELOPMENT BRANCH

SUBJECT:    VAS GRADIENT WINDS INTRODUCED TO AVIATION MODEL AND
            GDAS ANALYSES

(THE FOLLOWING INFORMATION WAS PROVIDED BY DR. STEVE LORD,
REGIONAL AND MESOSCALE MODELING BRANCH, NMC)

Wind vectors derived from the gradient of GOES-7 VAS temperature
retrievals were introduced to the Aviation and GDAS analyses at
1800 UTC on January 5, 1994.  On average, some 600-700 vectors
are generated north of 25 degrees North latitude over land and
ocean.  Only winds over ocean (30-40 percent of the total number)
are used by the analyses.  The data are produced four times each
day (0000, 0600, 1200 and 1800 UTC) at 700, 500, and 400 mb. 
Normally, the impact of these winds on the global analyses and
subsequent forecasts is small.  However, it is expected that they
will provide a positive impact in certain mesoscale events.

For more information, contact Steve Lord at (301-763-8301).

END
NNNNZCZC WSHPNSNMC ALL
TTAA00 KWSH DDHHMM

NATIONAL TECHNICAL INFORMATION MESSAGE 94-06
NATIONAL WEATHER SERVICE HEADQUARTERS
345 PM EDT THU MAR 17 1994

TO:         ALL USERS OF THE SIGNIFICANT WEATHER GRAPHICS
            (NMCGPH9PW AND NMCGPH9RW)

FROM:       JOHN F. MACHOWSKI
            ACTING CHIEF, SERVICES DEVELOPMENT BRANCH

SUBJECT:    CHANGE IN ISSUANCE TIME OF SIGNIFICANT WEATHER
            GRAPHICS

(THE FOLLOWING INFORMATION WAS PROVIDED BY DAVE FEIT, CHIEF,
MARINE FORECASTING BRANCH, NMC)

Effective Monday, April 4, 1994, the 24- and 48-hour significant
weather graphics (NMCGPH9PW and NMCGPH9RW, respectively) will be
available at 1245 UTC rather than 0800 UTC.

If you have any questions, contact Dave Feit at (301-763-8442).

END