[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211753
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST WED DEC 21 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM
THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON
SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 8N22W 5N33W 4N43W EQ51W.
SCATTERED MODERATE/STRONG CONVECTION IS LOCATED WITHIN 120 NM TO
THE SOUTH OF THE ITCZ AXIS FROM 12W-40W. ISOLATED WEAK TO
MODERATE SHOWERS ARE LOCTAED WITHIN 150 NM TO THE NORTH OF THE
ITCZ AXIS BETWEEN 12W-40W.

...DISCUSSION...

THE GULF OF MEXICO AND THE WESTERN ATLANTIC OCEAN ...
A 1030 MB SURFACE HIGH OVER THE LA/AR BORDER CONTINUES TO BUILD
INTO THE GULF OF MEXICO. THIS RIDGE IS CASUING FAIR WEATHER OVER
THE SOUTHEAST U.S. AND THE CENTRAL AND EASTERN GULF. THIS
SURFACE HIGH IS FORECAST BY MANY OF THE GLOBAL MODELS TO SLIDE
TO THE SE OVER THE NEXT COUPLE OF DAYS. A WEAK AREA OF LOW
PRESSURE IN THE WESTERN GULF OF MEXICO OFF THE TX/MX COASTLINE
NEAR 26N96W HAS DEVELOPED THIS MORNING. AN ASSOCIATED TROUGH
AND/OR A POSSIBLE FORMATIVE COLD FRONT DRAPES FROM THIS LOW TO
THE MEXICAN COASTLINE NEAR 21N98W. THE MOST ORGANIZED SHOWERS
AND DENSE OVERCAST SKIES ARE WITHIN 150 NM TO THE NE OF THE LOW
AND WITHIN 30 NM ON EITHER SIDE OF THE TROUGH OR FRONTAL
BOUNDARY. NONE OF THE DYNAMICAL MODELS HAVE INITIALIZED THIS LOW
IN THE 12Z MODEL RUNS THEREFORE THE MODELS DO NOT HAVE A FUTURE
FORECAST POSITION FOR THE LOW. A SLOW MOVING WEAK AREA OF LOW
PRESSURE IS LOCATED EAST OF CENTRAL FLORIDA NEAR 29N75W. A
STATIONARY FRONT EXTENDS FROM THIS WEAK LOW TO WESTERN CUBA AND
TOWARDS CENTRAL AMERICA NEAR 17N87W. PERSISTENT BROKEN TO
OVERCAST SKIES WITH ISOLATED SHOWERS EXIST NEAR THE LOW AND
WITHIN 60 NM ON EITHER SIDE OF THE FRONT. THIS AREA OF LOW
PRESSURE AND STATIONARY FRONT ARE FINALLY FORECAST TO MOVE AWAY
FROM THE AREA IN THE NEXT 24 HOURS...CLEARING OUT THE SKIES AS
HIGH PRESSURE BUILDS IN.

THE CARIBBEAN SEA...
AN UPPER HIGH NE OF PUERTO RICO NEAR 21N 66W IS SUPPORTING
MOSTLY FAIR WEATHER EAST OF 75W. DRY UPPER LEVEL AIR IS EVIDENT
ON WATER VAPOR IMAGERY IN THIS REGION. FROM 75W WESTWARD BROKEN
SKIES AND ISOLATED SHOWERS ARE STREAMING NORTH/NORTHEASTWARD ON
THE RETURN SIDE OF THE UPPER HIGH AND AHEAD OF THE STATIONARY
FRONT. BROKEN TO OVERCAST SKIES WITH SCATTERED SHOWERS ARE NEAR
THE YUCATAN PENISULA...WHICH IS CLOSE TO THE STATIONARY FRONT
TRADE WINDS NEAR 15 KTS COVER MUCH OF THE AREA. ISOLATED SHOWERS
ARE MOVING ACROSS THE LEEWARD ISLANDS IN THE TRADE WIND FLOW.

THE REST OF THE ATLANTIC OCEAN...
A 1023 MB SURFACE HIGH IS CENTERED NEAR 27N39W. THIS SURFACE
HIGH AND THE UPPER LEVEL HIGH NEAR 21N 66W ARE SUPPLYING FAIR
WEATHER AND DRY UPPER LEVEL AIR ACROSS MUCH OF THE ATLANTIC
BASIN BETWEEN 30W-70W SOUTH OF 25N.  THE GLOBAL MODELS KEEP THIS
HIGH IN PLACE OR DRIFT IT TO THE SW OVER THE NEXT DAY OR TWO. A
WEAKENING AREA OF LOW PRESSURE IN THE NE ATLANTIC NEAR 28N22W IS
MOVING TO THE NE. THIS LOW WILL LIKELY DISSIPATE WITHIN THE NEXT
DAY. A WSWLY JET BETWEEN 70KT AND 90 KT EXTENDS FROM 12N35W TO
PEAK VALUES NEAR THE CORE OF 100 KTS OVER AFRICA NEAR 26N9W.

$$
JC/MT




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