AXNT20 KNHC 072345
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED JAN 07 2009

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...THE ITCZ...

ITCZ IS CENTERED ALONG 7N11W 3N18W 2N30W 2N44W AND INTO NE 
BRAZIL NEAR 1N51W. SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS 
ARE FROM  3S-5N BETWEEN 3N-28N.
...DISCUSSION...

GULF OF MEXICO...
AT OF 2100 UTC...THE COLD FRONT HAS MOVED INTO S FLORIDA NEAR 
WEST PALM BEACH AND INTO THE GULF NEAR NAPLES EXTENDING SW 
ACROSS THE S GULF INTO THE BAY OF CAMPECHE AND ENTERING MEXICO 
NEAR VERACRUZ. DOPPLER RADAR INDICATES A BAND OF SHOWERS AND 
ISOLATED THUNDERSTORMS ALONG THE FRONT WITH SCATTERED SHOWERS 
WITHIN 150 NM WNW OF THE FRONT. ISOLATED SHOWERS ARE SE AHEAD OF 
THE FRONT. THE UPPER LEVEL TROUGH SUPPORTING THE FRONT IS OVER 
THE E US COAST. BEHIND THE FRONT...SURFACE HIGH PRESSURE IS 
BUILDING OVER THE NW GULF BRINGING DRY AIR AND CLEAR SKIES FROM 
THE ERN FLORIDA PANHANDLE TO TEXAS AND N MEXICO. WINDS OF 20 TO 
30 KT ARE IN THE NW GULF W OF 90W. AN UPPER LEVEL RIDGE COVERING 
THE W CARIBBEAN EXTENDS INTO THE SRN GULF AND SW ATLC. THE FRONT 
IS EXPECTED TO CONTINUE MOVING EWD AND SHOULD EXIT THE GULF LATE 
TONIGHT INTO THURSDAY MORNING. 

CARIBBEAN SEA...
A MID/UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE W CARIBBEAN 
EXTENDING N FROM AN UPPER LEVEL HIGH NEAR 14N77W ACROSS CUBA 
COVERING SRN PORTIONS OF THE GULF OF MEXICO AND THE SW ATLC. AN 
UPPER LEVEL TROUGH FROM THE CENTRAL ATLANTIC COVERS THE 
REMAINDER OF THE E CARIBBEAN E OF 67W. DRY AIR IN SUBSIDENCE 
COVERS THE ENTIRE AREA. HOWEVER...DUE TO LOW LEVEL INSTABILITY 
PATCHES OF LOW CLOUDS AND ISOLATED SHOWERS EXIST ACROSS THE 
CARIBBEAN...ESPECIALLY ALONG THE E COAST OF PANAMA AND COSTA 
RICA. E TO NE WINDS OF 20 TO 25 KT ARE OBSERVED ACROSS THE 
BASIN. THE COLD FRONT CURRENTLY IN THE GULF OF MEXICO IS 
EXPECTED TO ENTER THE CARIBBEAN LATE TONIGHT/THURSDAY MORNING 
AND THEN SLOWLY DISSIPATE THROUGH FRI. 

ATLANTIC OCEAN...
AT OF 2100 UTC...THE COLD FRONT HAS MOVED OFF THE E COAST OF THE 
US ENTERING THE REGION NEAR 30N80W CROSSING FLORIDA BETWEEN WEST 
PALM BEACH AND NAPLES INTO THE SW GULF OF MEXICO. GALE FORCE 
WINDS ARE WITHIN 180 NM E OF FRONT AND N OF 29N AND ARE EXPECTED 
TO CONTINUE FOR THE NEXT 12 HOURS. AN UPPER RIDGE COVERING THE W 
CARIBBEAN EXTENDS ACROSS CUBA INTO THE SW ATLC. THE REMAINDER OF 
THE ATLC IS DOMINATED BY AN UPPER LEVEL TROUGH/RIDGE/TROUGH 
PATTERN. THE UPPER LEVEL TROUGH IS LOCATED W OF THE ANTILLES AND 
SUPPORTS SCATTERED SHOWER ACTIVITY FROM 10N-20N BETWEEN 28W-46W 
AND ISOLATED SHOWERS FROM 20N-30N BETWEEN 35W-48W. HOWEVER...THE 
SURFACE IS DOMINATED BY HIGH PRESSURE E OF 75W WITH A 1026 MB 
HIGH CENTERED NEAR 30N37W. THE COLD FRONT IS EXPECTED TO MOVE 
ACROSS THE W ATLC AND WEAKEN IN THE CENTRAL ATLC BY SAT. SURFACE 
HIGH PRESSURE IS EXPECTED TO DOMINATE THE REMAINDER OF THE BASIN 
OVER THE NEXT 24 HOURS.

$$
WALTON/HUFFMAN