000
AXNT20 KNHC 131803
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE DEC 13 2011

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH LIBERIA NEAR 7N10W TO 6N12W.
THE ITCZ CONTINUES FROM 6N12W TO 4N21W 7N32W...TO THE COAST OF 
NORTHEASTERN BRAZIL/NORTHEASTERN FRENCH GUIANA. RAINSHOWERS ARE 
POSSIBLE WITHIN 60 TO 120 NM ON EITHER SIDE OF 2N10W 7N20W 7N30W
6N40W 6N50W 7N60W...AND TO THE SOUTH OF 4N TO THE EAST OF 10W.

...DISCUSSION...

THE GULF OF MEXICO...
UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA.
A SURFACE RIDGE PASSES THROUGH THE WESTERN FLORIDA PANHANDLE
INTO THE CENTRAL GULF OF MEXICO...BEYOND THE YUCATAN PENINSULA
INTO GUATEMALA. LOW CLOUDS...FOG...AND POSSIBLE RAINSHOWERS
HAVE BEEN OBSERVED IN THE COASTAL PLAINS/COASTAL WATERS FROM
90W TO THE NORTHERN ISTHMUS OF TEHUANTEPEC OF MEXICO.
LOW CLOUDS HAVE BEEN OBSERVED TO THE NORTH OF 24N TO THE EAST
OF 90W. RE POSSIBLE ALONG THE GULF COAST OF MEXICO FROM THE 
COASTAL PLAINS OF THE NORTHERN ISTHMUS OF TEHUANTEPEC TO THE 
TEXAS COAST...AND IN THE COASTAL OF THE U.S.A. FROM TEXAS TO 
THE SURFACE RIDGE IS EXPECTED TO REMAIN STATIONARY THROUGH 
WEDNESDAY. IT WILL SHIFT EASTWARD INTO THE SOUTHWESTERN NORTH
ATLANTIC OCEAN ON THURSDAY...ALLOWING A WEAK FRONTAL BOUNDARY TO 
EMERGE OFF THE TEXAS AND LOUISIANA GULF COAST BY LATE THURSDAY.

THE CARIBBEAN SEA...

AN UPPER LEVEL INVERTED TROUGH IS ALONG 13N77W BEYOND 9N79W. 
LARGE-SCALE UPPER LEVEL ANTICYCLONIC WIND FLOW IS ASSOCIATED
WITH A RIDGE THAT EXTENDS FROM CENTRAL VENEZUELA...ACROSS 
NORTHERN COASTAL COLOMBIA...TOWARD THE NORTHWESTERN CORNER OF 
THE AREA. THE MONSOON TROUGH IS ALONG 12N73W AT THE COLOMBIA 
COAST TO 11N80W...BEYOND 10N84W IN CENTRAL COSTA RICA. SCATTERED 
STRONG RAINSHOWERS ARE FROM 10N TO 12N BETWEEN 79W AND COASTAL 
NICARAGUA. RAINSHOWERS ARE POSSIBLE ELSEWHERE TO THE SOUTH OF 
13N TO THE WEST OF 73W.

THE ATLANTIC OCEAN...

AN UPPER LEVEL TROUGH PASSES THROUGH 32N64W TO 25N64W.
A SURFACE TROUGH EXTENDS FROM A 1012 MB LOW PRESSURE CENTER
THAT IS NEAR 31N62W...TO 25N65W AND 22N62W. ISOLATED MODERATE 
RAINSHOWERS ARE WITHIN 60 TO 90 NM ON EITHER SIDE OF 14N51W 
20N56W 26N58W...AND WITHIN 120 NM ON EITHER SIDE OF 26N58W
BEYOND 32N58W. UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS
THE ATLANTIC OCEAN TO THE NORTH OF 17N BETWEEN 36W AND 50W.
A LARGE-SCALE UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC 
CIRCULATION CENTER THAT IS OFF THE COAST SOUTHERN
MOROCCO...THROUGH 24N18W...TO A 20N27W CYCLONIC CIRCULATION 
CENTER TO 13N38W AND 10N40W. SURFACE ANTICYCLONIC WIND FLOW
IS TO THE NORTH OF THE ITCZ TO THE EAST OF 55W...MOVING
AROUND A 1031 MB HIGH PRESSURE CENTER THAT IS NEAR 33N33W.

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

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MT