000
AXNT20 KNHC 190538
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST SAT DEC 19 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0515 UTC.

...THE ITCZ...

FROM COASTAL SIERRA LEONE NEAR 9N13W TO 6N20W TO 3N35W 4N44W...
INTO EXTREME NORTHEASTERN BRAZIL NEAR 2N51W. SHOWERS ARE POSSIBLE
FROM 6N TO 10N BETWEEN 16W AND 24W...TO THE SOUTH OF 10N BETWEEN
24W AND 50W...AND OVER THE WATERS TO THE SOUTH OF 7N BETWEEN
50W AND 54W.

...DISCUSSION...

THE GULF OF MEXICO AND THE ATLANTIC OCEAN TO THE WEST OF 70W...
UPPER LEVEL SOUTHWESTERLY FLOW IS PUSHING MOISTURE FROM THE AREA
OF 10N BETWEEN 90W AND 110W IN THE EASTERN PACIFIC OCEAN TOWARD
THE NORTHEAST. THE UPPER LEVEL MOISTURE CROSSES MEXICO...INTO 
THE CENTRAL GULF OF MEXICO...TOWARD SOUTHWESTERN FLORIDA.
THE MOISTURE IN THE UPPER LEVEL SOUTHWESTERLY FLOW IS MOVING ON 
TOP OF DEEP LAYER CYCLONIC FLOW THAT COVERS AT LEAST THE 
NORTHERN HALF OF THE AREA. THE DEEP LAYER CYCLONIC FLOW IS 
STEERING THE CURRENT COLD FRONT THAT IS MOVING ACROSS FLORIDA.
THE COLD FRONT PASSES THROUGH 31N80W IN THE ATLANTIC OCEAN...
TO FLORIDA JUST TO THE EAST OF LAKE OKEECHOBEE...TO THE SOUTHERN
TIP OF FLORIDA/THE FLORIDA KEYS...TO WESTERN CUBA AND INTO THE
NORTHWESTERN CARIBBEAN SEA NEAR 20N84W. SHOWERS AND POSSIBLE
THUNDERSTORMS ARE FROM 17N TO JAMAICA BETWEEN 78W AND 79W...
ON THE CARIBBEAN SEA COAST OF CUBA BETWEEN THE EASTERN END OF 
CUBA AND 81W...AROUND THE BAHAMAS FROM 24N TO 28N BETWEEN 74W
AND 79W...AND TO THE NORTH OF 30N TO THE WEST OF 70W.
SURFACE HIGH PRESSURE HAS BEEN BUILDING INTO THE GULF OF MEXICO
TO THE WEST OF THE COLD FRONT.

THE CARIBBEAN SEA...
UPPER LEVEL ANTICYCLONIC FLOW...THAT ORIGINATES OVER NORTHERN 
SECTIONS OF SOUTH AMERICA...COVERS THE AREA TO THE SOUTH OF 14N.
ISOLATED MODERATE SHOWERS ARE IN COASTAL SECTIONS OF THE 
DOMINICAN REPUBLIC BETWEEN THE EASTERN END OF THE COUNTRY AND
AND 18N70W. UPPER LEVEL SOUTHWESTERLY WIND FLOW IS PUSHING
MOISTURE FROM THE EASTERN PACIFIC OCEAN ACROSS CENTRAL AMERICA 
AND INTO THE SOUTHWESTERN CORNER OF THE AREA...TO THE SOUTH OF
THE LINE FROM 16N82W TO 11N74W. THE SURFACE PRESSURE GRADIENT
IS WEAK.
  
THE ATLANTIC OCEAN TO THE EAST OF 70W...
A DEEP LAYER TROUGH IN THE EAST CENTRAL ATLANTIC OCEAN...THAT 
PASSES THROUGH 32N37W TO 27N36W TO 21N40W TO 19N50W...SUPPORTS
A COLD FRONT THAT PASSES THROUGH 31N36W TO 26N40W TO 23N45W. THE 
FRONT CONTINUES AS STATIONARY FROM 23N45W TO 21N60W TO 25N70W.
SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 30 NM TO 60 NM ON 
EITHER SIDE OF 22N43W 25N38W 28N35W BEYOND 31N31W. BROKEN LOW TO 
MIDDLE LEVEL CLOUDS AND POSSIBLE PRECIPITATION FROM 21N TO 23N
BETWEEN BETWEEN 43W AND 64W...AND FROM 23N TO 27N BETWEEN 64W 
AND 70W. A 1018 MB HIGH PRESSURE CENTER IS NEAR 22N27W. A SECOND
1018 MB HIGH PRESSURE CENTER IS NEAR 28N62W.

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