000
AXNT20 KNHC 100002
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST TUE DEC 09 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.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N8W 3N26W 3N45W 2N51W. SCATTERED 
MODERATE CONVECTION IS WITHIN 150 NM N OF THE ITCZ FROM 
23W-30W...WITHIN 120 NM S OF THE ITCZ FROM 27W-30W AND FROM 5N-7N 
BETWEEN 38W-42W. 

...DISCUSSION...

GULF OF MEXICO...
AT 2100 UTC...A COLD FRONT ENTERS THE GULF OF MEXICO NEAR PANAMA 
CITY FLORIDA EXTENDING SW ALONG 26N92W TO A 1006 MB LOW OFF THE 
MEXICAN COAST NEAR 24N97W CONTINUING S ALONG 22N96W TO THE COAST OF 
MEXICO BETWEEN TUXPAN AND VERACRUZ NEAR 21N07W. SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS ARE OVER THE FAR NE GULF N OF 28N E OF 89W 
WITH A WELL DEFINED ROPE CLOUD AND ISOLATED SHOWERS ALONG THE 
IMMEDIATE FRONTAL BOUNDARY. THE UPPER LOW SUPPORTING THIS FRONT IS 
MOVING NE OVER NEW ENGLAND AND E CANADA. AN UPPER RIDGE IS ANCHORED 
OVER S MEXICO AND EXTENDS OVER THE GULF ALONG 20N94W TO S FLORIDA. A 
SURFACE RIDGE OVER THE CENTRAL PLAIN STATES IS BEGINNING TO MOVE S  
INTO THE NW GULF. EXPECT THE FRONT TO REACH FROM THE FLORIDA BIG 
BEND TO SOUTH OF TAMPICO MEXICO THU WITH THE WESTERN PORTION 
STALLING WHILE THE EASTERN PORTION WILL CONTINUE SE OVER S FLORIDA 
BY LATE THU. 

CARIBBEAN SEA...
A BROAD UPPER RIDGE EXTENDS FROM THE NW CARIBBEAN INTO THE W ATLC 
GIVING THE ENTIRE BASIN STRONG SUBSIDENCE. HOWEVER...LOW LEVEL 
SCATTERED SHOWERS ARE OVER THE N CARIBBEAN N OF 16N TO OVER THE 
GREATER ANTILLES E OF 80W TO OVER THE LEEWARD ISLANDS. AN UPPER 
RIDGE OVER SOUTH AMERICA IS DRAWING MOISTURE N ACROSS PANAMA INTO 
THE SW CARIBBEAN GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS S OF 11N BETWEEN 77W-83W. SURFACE RIDGE N OF THE 
CARIBBEAN IS MAINTAINING FRESH TO STRONG EASTERLY TRADE WINDS ACROSS 
THE REGION. 

ATLANTIC OCEAN...
A BAND OF SHOWERS AND SCATTERED THUNDERSTORMS ARE WITHIN 60 NM OF 
LINE THROUGH 32N78W ACROSS NE FLORIDA NEAR JACKSONVILLE INTO THE 
GULF OF MEXICO AHEAD OF THE FRONTAL BOUNDARY THAT IS CURRENTLY IN 
THE GULF OF MEXICO. SURFACE HIGH ANCHORED BY A 1023 MB HIGH NEAR 
29N56W DOMINATES MUCH OF THE ATLC WITH A WEAKNESS OVER THE N/CENTRAL 
ATLC WHERE A FRONTAL BOUNDARY IS JUST N OF THE REGION. A SURFACE 
TROUGH ENTERS THE CENTRAL ATLC NEAR 32N37W EXTENDING SW TO 27N45W 
WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS MOVING 
RAPIDLY EASTWARD WITHIN 75 NM OF LINE FROM 29N36W TO BEYOND 32N32W. 
THUS THE REMAINDER OF THE ATLC IS UNDER FAIR WEATHER THIS EVENING. 

$$
WALLACE