000
AXNT20 KNHC 231126
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST TUE DEC 23 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1045 UTC.

...THE ITCZ...
ITCZ IS CENTERED ALONG 9N10W 4N21W 4N46W 3N52W. CLUSTERS OF 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-6N E 
OF 29W ACROSS THE PRIME MERIDIAN. SCATTERED SHOWERS AND POSSIBLE 
ISOLATED THUNDERSTORMS ARE FROM 3N-10N BETWEEN 42W-57W INCLUDING 
THE SOUTH AMERICAN COAST. 
  
...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT EXTENDS FROM THE W ATLC INTO THE FLORIDA STRAITS 
NEAR 23N80W CONTINUING AS A STATIONARY FRONT ALONG 23N91W TO A 
1016 MB SURFACE LOW LOCATED OFF THE TEXAS COAST NEAR 26N96W WITH 
A SECOND STATIONARY FRONT S FROM THE LOW TO 32N97W. A SURFACE 
TROUGH EXTENDS N FROM THE SURFACE LOW TO OVER E TEXAS NEAR 
CORPUS CHRISTI. A SURFACE RIDGE EXTENDS FROM OVER THE E US AND 
THE N GULF BRIDGING THE FRONT DRAPED ACROSS THE GULF. BROKEN/ 
OVERCAST STRATOCUMULUS LOW CLOUDS WITH ISOLATED SHOWERS COVERING 
MUCH OF THE GULF BUT IS BEGINNING TO PUSH N AS RETURN FLOW 
AROUND THE SURFACE RIDGE. MODERATE/STRONG SUBSIDENCE AND DRY 
STABLE AIR ARE NOTED ACROSS S FLORIDA AND THE S GULF WATERS 
MAINLY S OF 25N. 

CARIBBEAN SEA...
THE CARIBBEAN REMAINS UNDER THE INFLUENCE OF A BROAD UPPER HIGH 
CENTERED NEAR 14N69W AND ENCOMPASSES THE ENTIRE CARIBBEAN BASIN 
WITH STRONG SUBSIDENCE IN DRY AIR. THIS UPPER LEVEL FEATURE ALSO 
ENVELOPS CENTRAL AMERICA AND THE N PORTION OF SOUTH AMERICA. 
HOWEVER...AREAS OF SHALLOW LOW LEVEL MOISTURE CONTINUES TO 
STREAM ACROSS THE BASIN USHERED IN ON NE-E TRADE WINDS WITH 
ISOLATED SHOWERS DOTTING MOST OF THE ENTIRE CARIBBEAN INCLUDING 
THE LESSER ANTILLES. LOOKING AHEAD...STRONG HIGH PRESSURE IS 
FORECAST TO BUILD N OF AREA WITH INCREASING TRADE WINDS EXPECTED 
OVER THE TROPICAL ATLC AND MUCH OF THE CARIBBEAN TODAY THROUGH 
FRI.
 
ATLANTIC OCEAN...
A COLD FRONT ENTERS THE W ATLC NEAR 32N60W AND EXTENDS ACROSS 
THE BAHAMAS NEAR 24N76W INTO THE FLORIDA STRAITS NEAR 23N80W AS 
A STATIONARY BOUNDARY INTO THE GULF OF MEXICO. BROKEN/OVERCAST 
STRATOCUMULUS LOW CLOUDS WITH ISOLATED SHOWERS ARE WITHIN 150 NM 
NW OF THE FRONT WITH COLD AIR STRATOCUMULUS CLOUDS COVERING THE 
REMAINDER OF THE AREA N OF THE FRONT. A BROAD UPPER LEVEL RIDGE 
EXTENDS FROM THE CARIBBEAN WITH AXIS ACROSS THE VIRGIN/LEEWARD 
ISLANDS NE TO BEYOND 32N47W. MOSTLY FAIR WEATHER CONDITIONS ARE 
OBSERVED E OF THE COLD FRONT TO 30W WITH A WEAK 1026 MB HIGH 
NEAR 27N56W. A SURFACE TROUGH IS IN THE CENTRAL ATLC EXTENDING 
ALONG 48W FROM 16N-25N SUPPORTED BY UPPER LEVEL TROUGHING 
EXTENDING FROM THE E/CENTRAL ATLC NEAR 32N23W SW ALONG 21N34W 
INTO THE TROPICS ALONG 15N44W AND THEN W TO NEAR 13N55W. UPPER 
DIFFLUENCE E OF THIS UPPER TROUGH ALONG WITH AN UPPER RIDGE 
AMPLIFIED ALONG THE W AFRICAN COAST IS ENHANCING SCATTERED 
SHOWERS WITHIN 175 NM EITHER SIDE OF A LINE FROM 12N33W TO OVER 
W AFRICA NEAR MAURITANIA AND WESTERN SAHARA. NE TO E WINDS HAVE 
INCREASED ACROSS THE TROPICS AND WILL CONTINUE THROUGH FRI. 

$$
WALLACE