000
AXNT20 KNHC 282351
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST TUE DEC 28 2010

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...

FROM THE COASTAL BORDER OF GUINEA AND SIERRA LEONE NEAR 9N13W TO
4N24W 4N38W INTO EXTREME NORTHEASTERN BRAZIL NEAR 1N50W. BROKEN 
TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE RAINSHOWERS
TO LOCALLY STRONG THUNDERSTORMS ARE WITHIN 180 NM ON EITHER SIDE
OF 6N8W 5N17W 4N38W 3N50W.

...DISCUSSION...

THE GULF OF MEXICO...

BROAD AND GRADUAL MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND 
FLOW SPANS THE AREA THAT IS BETWEEN FLORIDA AND CENTRAL MEXICO.
A RIDGE IS DEVELOPING GRADUALLY ACROSS THE AREA. BROAD SURFACE 
ANTICYCLONIC FLOW COVERS THE AREA...MOVING AROUND A 1028 MB HIGH 
PRESSURE CENTER THAT IS NEAR 30N88W...JUST OFF THE COAST OF 
SOUTHWESTERN ALABAMA.

FROM THE ATLANTIC OCEAN TO THE WEST OF 48W...ACROSS THE 
NORTHEASTERN CORNER OF THE CARIBBEAN SEA INTO THE CENTRAL
SECTIONS OF THE CARIBBEAN SEA...

A TROUGH ON WATER VAPOR IMAGERY PASSES THROUGH 33N55W TO 28N60W 
TOWARD THE SOUTHERN BAHAMAS/THE NORTHERN BORDER BETWEEN THE 
DOMINICAN REPUBLIC AND HAITI. THE TROUGH SUPPORTS THE COLD
FRONT THAT PASSES THROUGH 32N51W TO 23N57W TO 20N61W...ACROSS 
THE VIRGIN ISLANDS TO 14N74W IN THE CENTRAL CARIBBEAN SEA.
BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE 
RAINSHOWERS ARE WITHIN 120 NM ON EITHER SIDE OF THE LINE THAT 
PASSES THROUGH 32N45W 26N52W TO 20N63W IN THE ATLANTIC OCEAN. 
BROKEN MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION ARE WITHIN 
210 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 20N61W 
16N68W TO 12N74W IN THE CARIBBEAN SEA. GALE FORCE WIND 
CONDITIONS ARE TO THE NORTH OF 27N BETWEEN THE COLD FRONT
AND 67W WITH SEA HEIGHTS RANGING FROM 18 FEET TO 28 FEET IN 
NORTHWESTERLY SWELL...AND TO THE NORTH OF 27N WITHIN 180 NM
TO THE EAST OF THE FRONT WITH SEA HEIGHTS RANGING FROM
11 FEET TO 15 FEET.

THE REST OF THE CARIBBEAN SEA...

RAINSHOWERS AND THUNDERSTORMS ARE OCCURRING FROM 12N TO 15N 
BETWEEN 77W AND 81W. THE PRECIPITATION IS NEAR A LOW LEVEL TO
MIDDLE LEVEL TROUGH THAT IS ALONG 78W/79W FROM THE PANAMA COAST
TO 15N. ISOLATED MODERATE RAINSHOWERS ARE IN NORTHWESTERN 
VENEZUELA FROM 8N TO 11N BETWEEN 67W AND 72W...IN BROAD LOW 
LEVEL-TO-MIDDLE LEVEL CYCLONIC FLOW. SURFACE NORTHEASTERLY WIND 
FLOW COVERS THE AREA TO THE WEST OF THE COLD FRONT. SURFACE 
EASTERLY TO NORTHEASTERLY WIND FLOW IS TO THE EAST OF THE FRONT.

THE REST OF THE ATLANTIC OCEAN...

AN EASTERN ATLANTIC OCEAN TROUGH IN WATER VAPOR IMAGERY PASSES
THROUGH 32N17W TO 22N23W TO 10N27W. THIS TROUGH SUPPORTS A COLD 
FRONT THAT PASSES THROUGH 32N15W...ON TOP OF THE CANARY 
ISLANDS...TO 24N23W. ANY APPARENT PRECIPITATION THAT IS FOUND
IN SATELLITE IMAGERY IS TO THE NORTH OF 31N BETWEEN 13W AND 23W.
A 1020 MB HIGH PRESSURE CENTER IS NEAR 29N38W. SURFACE 
ANTICYCLONIC WIND FLOW COVERS THE AREA TO THE NORTH OF 20N
BETWEEN THE 32N15W 21N40W COLD FRONT AND THE 32N51W 20N61W
COLD FRONT.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
MT