000
AXNT20 KNHC 111805
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST THU DEC 11 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 THE 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1745 UTC.

...THE ITCZ...

FROM NORTHERN LIBERIA TO 5N20W 3N30W 2N40W 1N46W...INTO EXTREME 
NORTHEASTERN BRAZIL ALONG THE EQUATOR AT 50W. ISOLATED MODERATE 
SHOWERS AND POSSIBLE THUNDERSTORMS ARE TO THE SOUTH OF 8N
TO THE EAST OF 58W.

...DISCUSSION...

THE GULF OF MEXICO...
THE CURRENT COLD FRONT IS ANALYZED COMING FROM THE STRAIGHTS OF 
FLORIDA ALONG 24N82W...BECOMING STATIONARY FRONT AT 24N85W AND 
CONTINUING ALONG 24N90W 24N94W CURVING TO A SURFACE 1014 MB LOW AT 
22N94W. SATELLITE IMAGERY INDICATES BROKEN TO OVERCAST MULTILAYERED 
CLOUDS OVER THE CENTRAL AND NORTHERN BASIN WITH POSSIBLE 
PRECIPITATION FROM 28N TO 26N BETWEEN 90W AND 95W. DOPPLER RADAR 
SHOWS A LINE OF SHOWERS ENTERING THE NORTHERN FLORIDA PENINSULA AND 
PANHANDLE 29N FROM 28N BETWEEN 82W 84W. RADAR IMAGERY ALSO SHOWS 
HEAVIER SHOWERS WITH POSSIBLE EMBEDDED THUNDERSTORMS TO THE SOUTHERN 
TIP OF THE FLORIDA PENINSULA FROM 25N TO 24N BETWEEN 79W AND 82W.

THE CARIBBEAN SEA...
AN UPPER LEVEL RIDGE IS COVERING CARIBBEAN BRINGING STRONG 
SUBSIDENCE AND DRY AIR OVER MUCH OF THE AREA...BRINGING GENERALLY 
FAIR WEATHER ACROSS THE BASIN...EXCEPT FOR POSSIBLE PRECIPITATION 
OVER THE WATERS FROM 19N TO 15N BETWEEN 62W AND 85W.THESE SHOWERS 
ARE AFFECTING PORTIONS OF PUERTO RICO...HISPANIOLA...AND JAMAICA. 
FRESH TO STRONG TRADE WINDS ARE ACROSS THE MAJORITY OF THE AREA. 
EXPECT MOISTURE ASSOCIATED WITH THE COLD FRONT ACROSS THE GULF OF 
MEXICO TO REACH THE NW CARIBBEAN LATER TONIGHT...BRINGING A HIGHER 
CHANCE OF SHOWERS TO THAT AREA. 

THE ATLANTIC OCEAN...
A DEEP LAYER WESTERN ATLANTIC OCEAN TROUGH SUPPORTS THE CURRENT COLD 
FRONT THAT PASSES THROUGH 30N65W TO THE STRAITS OF FLORIDA NEAR KEY 
WEST. MODERATE SHOWERS ARE 30 NM TO 60 NM ON EITHER SIDE OF THIS 
FRONT. ANOTHER COLD FRONT OVER THE EASTERN ATLANTIC FROM 30N16W TO 
25N22W IS SUPPORTED BY DEEP LAYER TROUGH LOCATED OVER THE 
NORTHWESTERN AFRICAN COAST. SCATTERED MODERATE SHOWERS TO ISOLATED 
STRONG THUNDERSTORMS ARE WITHIN 40 NM AHEAD OF THIS FRONT. BROAD 
UPPER LEVEL ANTICYCLONIC FLOW COVERS THE CENTRAL ATLANTIC BETWEEN 
THE TWO DEEP LAYER TROUGHS. A 1024 MB HIGH PRESSURE CENTER IS NEAR 
28N41W. THIS SURFACE HIGH PRESSURE IS EXPECTED TO MOVE SOUTHEASTWARD 
TO NEAR 26N38W.
 
$$

FG