000
AXNT20 KNHC 291730
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON DEC 29 2008

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 1645 UTC.

...THE ITCZ...

FROM THE LIBERIA/SIERRA LEONE BORDER NEAR 7N11W TO 4N29W TO
5N38W INTO EXTREME NORTHEASTERN BRAZIL NEAR 1N51W. STRONG 
SHOWERS AND THUNDERSTORMS FROM 1S TO 1N BETWEEN 49W AND 51W 
ALONG THE COAST OF EXTREME NORTHEASTERN BRAZIL. STRONG SHOWERS
AND THUNDERSTORMS ALSO FROM 4N TO 5N BETWEEN 27W AND 28W...
FROM 4N TO 5N BETWEEN 32W AND 33W...FROM 6N TO 7N BETWEEN 37W 
AND 38W. STRONG SHOWERS AND THUNDERSTORMS IN INDIVIDUAL CLUSTERS 
FROM 5N TO 11N BETWEEN 30W AND 40W. ISOLATED MODERATE SHOWERS
FROM 5N TO 10N BETWEEN 40W AND 60W. LINGERING SHOWERS POSSIBLE 
ELSEWHERE FROM THE EQUATOR TO 6N BETWEEN 20W AND 30W.

...DISCUSSION...

THE GULF OF MEXICO...
THE SOUTHERN PART OF A MIDDLE TO UPPER LEVEL TROUGH THAT IS
CROSSING THE U.S.A....TO THE EAST OF A LINE FROM EAST TEXAS
TO MISSOURI...REACHES ONLY AS FAR TO THE SOUTH AS SOUTHERN 
MISSISSIPPI. UPPER LEVEL SOUTHWESTERLY WIND FLOW CROSSES MEXICO 
AND TEXAS...FROM THE LOWER RIO GRANDE AREA...BEYOND THE 
SOUTHEASTERN U.S.A. A COLD FRONT PASSES FROM THE FLORIDA BIG 
BEND TO THE CENTRAL GULF OF MEXICO...TO THE MEXICO COAST NEAR 
19N96W. A SURFACE TROUGH IS ALONG 31N78W TO JUST NORTH OF LAKE 
OKEECHOBEE TO 24N87W. ISOLATED MODERATE SHOWERS ARE WITHIN 100 
NM TO THE NORTHWEST OF THE FRONT. SHOWERS ARE POSSIBLE IN 
CLUSTERS OF LOW CLOUDS...SOME IN LINES OF SURFACE-TO-LOW LEVEL 
CONFLUENT WIND FLOW...FROM 22N TO 27N BETWEEN 84W AND 88W. 

THE CARIBBEAN SEA...
UPPER LEVEL ANTICYCLONIC FLOW COVERS THE NORTHWESTERN CORNER OF 
THE AREA...NORTH OF 15N WEST OF 80W...INTO THE SOUTHEASTERN 
GULF OF MEXICO. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE 
SOUTHEASTERN ISLANDS TO NORTH CENTRAL COASTAL AND NORTHWESTERN 
VENEZUELA...TOWARD NORTHERN COLOMBIA. SHOWERS ARE POSSIBLE IN 
CLUSTERS OF LOW CLOUDS...SOME IN LINES OF SURFACE-TO-LOW LEVEL 
CONFLUENT WIND FLOW...FROM 12N TO 20N. MODERATE TO STRONG 
TRADEWINDS CONTINUE ACROSS THE AREA.

THE ATLANTIC OCEAN...
BROAD UPPER LEVEL ANTICYCLONIC FLOW...THANKS TO AN UPPER LEVEL
RIDGE IN THE WESTERN ATLANTIC WATERS...COVERS THE AREA WEST
OF 50W. A BROAD LONGWAVE MIDDLE TO UPPER LEVEL TROUGH PASSES
THROUGH 32N32W TO 23N35W. MORE THAN ONE SHORTWAVE TROUGH IS
MOVING THROUGH THE LONGWAVE FEATURE. PART OF THIS SAME TROUGH
WAS EXTENDING FROM 23N35W TO 18N46W TO THE SOUTHEASTERN
CARIBBEAN SEA ABOUT 48 HOURS AGO. A 1002 MB LOW PRESSURE CENTER 
HAS DEVELOPED NEAR 29N35W. A TROUGH EXTENDS FROM THE 29N35W
LOW PRESSURE CENTER TO 28N32W TO 24N33W TO 21N35W. A COLD FRONT 
EXTENDS FROM A 1002 MB GALE CENTER NEAR 33N25W TO 30N25W AND 
25N30W. WIDELY SCATTERED TO SCATTERED MODERATE SHOWERS AND 
POSSIBLE THUNDERSTORMS ARE NORTH OF 26N BETWEEN 30W AND 35W.
A 1024 MB HIGH PRESSURE CENTER IS NEAR 30N65W. BROAD SURFACE 
HIGH PRESSURE COVERS THE AREA NORTH OF 15N BETWEEN 46W AND 
77W...INCLUDING IN MUCH OF THE CARIBBEAN SEA.

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