000
AXNT20 KNHC 040001
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST THU DEC 03 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...

THE ITCZ AXIS IS CENTERED ALONG 5N7W 4N13W 6N39W 2N51W. CLUSTERS OF 
SCATTERED MODERATE CONVECTION ARE FROM 2N-6N BETWEEN 25W-39W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT EXTENDS ACROSS S FLORIDA FROM RIVERA 
BEACH NEAR 26N80W ENTERING THE GULF WATERS S OF CAPE ROMANO NEAR 
25N81W CONTINUING ACROSS THE SE GULF AND BECOMING STATIONARY NEAR 
THE YUCATAN CHANNEL TO OVER THE YUCATAN PENINSULA TO NEAR 20N90W. 
RADAR IMAGERY INDICATES A LINE OF SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS WITHIN 60 NM E OF THE FRONT WITH POSSIBLE ISOLATED 
SHOWERS WITHIN 180 NM W OF THE FRONT. THE FRONTAL SYSTEM IS 
SUPPORTED BY A BROAD UPPER TROUGH COVERING MUCH OF THE US. UPPER 
LEVEL MOISTURE IN SWLY FLOW ALOFT IS ENHANCING SHOWERS/THUNDERSTORM 
ACTIVITY. EXPECT THE FRONT TO STALL TONIGHT KEEPING MOISTURE AND 
SHOWER ACTIVITY ACROSS S FLORIDA FOR THE NEXT SEVERAL DAYS AS A LOW 
PRESSURE IS FORECAST TO FORM OFF THE TEXAS COAST FRI WITH AN 
ASSOCIATED COLD FRONT PUSHING TO THE E GULF BY SAT PRODUCING STRONG 
WINDS REACHING GALE FORCE FRI.

CARIBBEAN SEA...
A BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED IN THE E PACIFIC 
EXTENDING ACROSS NICARAGUA/HONDURAS THROUGH THE WINDWARD PASSAGE 
INTO THE W ATLC. STRONG SUBSIDENCE AND THE LACK OF MOISTURE IS NOTED 
ON WATER VAPOR IMAGERY WHICH ACCOMPANIES THE UPPER LEVEL 
ANTICYCLONIC CIRCULATION BRINGING TRANQUIL WEATHER AND FAIR SKIES TO 
MUCH OF THE BASIN. HOWEVER...WITH THE COLD FRONT IN THE GULF OF 
MEXICO EXTENDING JUST N OF THE YUCATAN CHANNEL...SCATTERED SHOWERS 
AND POSSIBLE ISOLATED THUNDERSTORMS ARE N OF 20N FROM 83W-86W AND A 
FEW ISOLATED LOW LEVEL SHOWERS ARE BEING USHERED IN ON FRESH TO 
STRONG TRADEWINDS ACROSS THE E CARIBBEAN AND LESSER ANTILLES MAINLY 
E OF 73W. THESE TRADEWINDS ARE BANKING LOW LEVEL CLOUDS WITH 
ISOLATED SHOWERS WITHIN 60 NM ALONG THE COAST FROM CENTRAL PANAMA TO 
THE NICARAGUA/COSTA RICA BORDER. 

ATLANTIC OCEAN...
A COLD FRONT EXTENDS ACROSS THE W ATLC IS ENTERING THE DISCUSSION 
AREA NEAR 32N76W ACROSS FLORIDA NEAR RIVERA BEACH INTO THE GULF OF 
MEXICO. SATELLITE IMAGERY SHOWS SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS WITHIN 75 NM OF THE FRONT N OF THE NORTHERN BAHAMA 
ISLANDS. ABUNDANT MOISTURE ALOFT AND SW FLOW OVER THE W ATLC ARE 
ENHANCING THIS SHOWER ACTIVITY. SURFACE HIGH PRESSURE NEAR 35N51W 
DOMINATES THE REMAINDER OF THE W ATLC. A SURFACE TROUGH EXTENDS FROM 
A WEAK 1020 MB LOW NEAR 30N41W INTO THE CENTRAL ATLANTIC ALONG 
26N42W 23N46W. SCATTERED SHOWERS ARE WITHIN 300 NM E OF THE TROUGH 
AXIS. THIS SYSTEM IS SUPPORTED BY A UPPER LEVEL TROUGH THAT EXTENDS 
THROUGH 32N39W TO A WEAK UPPER LOW NEAR 28N42W INTO THE TROPICS NEAR 
16N45W. THE E ATLC IS DOMINATED BY A SURFACE HIGH PRESSURE ANCHORED 
E OF THE AZORES. 

$$
GARCIA/WALLACE