000
AXNT20 KNHC 041148
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 AM EST SAT DEC 04 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1115 UTC.

...THE ITCZ...
 
FROM THE COAST OF SIERRA LEONE NEAR 8N13W TO 7N20W 7N32W TO 
4N38W...INTO NORTHEASTERN BRAZIL AND EASTERN FRENCH GUIANA NEAR 
4N52W. STRONG RAINSHOWERS AND THUNDERSTORMS ARE FROM 3N TO 8N
BETWEEN 41W AND 46W. SCATTERED MODERATE RAINSHOWERS TO ISOLATED
STRONG THUNDERSTORMS ARE FROM 4N TO 8N BETWEEN 47W AND 53W.
ISOLATED MODERATE RAINSHOWERS ARE ELSEWHERE TO THE SOUTH OF 10N 
TO THE EAST OF 55W...ESPECIALLY FROM 2N TO 5N TO THE EAST OF 26W.

...DISCUSSION...

THE GULF OF MEXICO...
MEXICO FINDS ITSELF ON THE EASTERN SIDE OF AN UPPER LEVEL RIDGE 
THAT CURVES FROM ARIZONA...THROUGH WESTERN AND NORTHERN 
MEXICO...INTO THE EASTERN PACIFIC OCEAN NEAR 15N103W. UPPER 
LEVEL NORTHWESTERLY WIND FLOW COVERS THE GULF OF MEXICO. THIS 
FLOW PATTERN IS DUE TO THE POSITIONING OF BEING ON THE EASTERN 
SIDE OF THE RIDGE/THE WESTERN SIDE OF THE UPPER LEVEL TROUGH 
THAT SUPPORTS THE CURRENT WESTERN ATLANTIC OCEAN TROUGH. SURFACE 
ANTICYCLONIC WIND FLOW MOVES AROUND A 1022 MB HIGH PRESSURE 
CENTER THAT IS NEAR 27N88W. A COLD FRONT MAY BE REACHING THE
NORTHWESTERN GULF COASTAL WATERS AFTER ABOUT THE NEXT 30 HOURS.

THE CARIBBEAN SEA...
MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW REMAINS IN THE 
NORTHWESTERN CORNER OF THE AREA. THIS CYCLONIC FLOW IS RELATED 
TO THE WESTERN ATLANTIC OCEAN TROUGH THAT SUPPORTS THE COLD 
FRONT THAT PASSES THROUGH THE TURKS ISLANDS...THROUGH THE 
WINDWARD PASSAGE...JUST OFF THE NORTHWESTERN COAST OF JAMAICA...
CURVING INTO EASTERN HONDURAS. THE UPPER LEVEL FLOW IS SOLIDLY 
FROM THE SOUTHWEST IN THE AREA THAT IS TO THE EAST OF THE LINE 
THAT GOES FROM NICARAGUA BEYOND HISPANIOLA. THE SURFACE WIND 
FLOW IS MOSTLY NORTHEASTERLY ACROSS THE AREA.

THE ATLANTIC OCEAN...
THE DEEP LAYER TROUGH THAT IS IN THE WESTERN ATLANTIC OCEAN 
SUPPORTS THE COLD FRONT THAT PASSES THROUGH 32N59W ACROSS THE
TURKS ISLANDS...THROUGH THE WINDWARD PASSAGE...TO EASTERN 
HONDURAS. RAINSHOWERS ARE POSSIBLE WITHIN 60 NM TO 90 NM ON 
EITHER SIDE OF 32N55W 26N60W 22N67W...TO THE WINDWARD PASSAGE.
COLD-AIR STRATIFORM CLOUDS COVER THE ATLANTIC OCEAN TO THE 
NORTHWEST OF THE COLD FRONT. A CYCLONIC CIRCULATION CENTER IN 
WATER VAPOR IMAGERY IS NEAR 35N30W. A TROUGH EXTENDS FROM THE
CYCLONIC CENTER TO 26N33W 20N34W TO 13N37W. A 983 MB GALE LOW 
PRESSURE CENTER IS NEAR 36N31W. A DISSIPATING COLD FRONT THAT 
ULTIMATELY CURVES AWAY FROM THE GALE LOW PRESSURE CENTER PASSES 
THROUGH 32N22W TO 20N30W AND 13N40W. A SECOND DISSIPATING COLD
FRONT IS WITHIN 180 NM TO THE NORTHWEST OF THE FIRST DISSIPATING
FRONT...AND THE SECOND DISSIPATING FRONT ULTIMATELY REACHES
12N50W. A DEVELOPING COLD FRONT IS WITHIN 150 NM TO 250 NM TO 
THE NORTHWEST OF THE SECOND DISSIPATING COLD FRONT...REACHING
25N41W. RAINSHOWERS ARE POSSIBLE TO THE NORTHEAST OF THE LINE
THAT PASSES THROUGH 32N39W TO 28N25W AND 27N17W.

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

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MT