000
AXNT20 KNHC 121805
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON DEC 12 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 THE BORDER AREA OF 
SOUTHWESTERN SENEGAL AND NORTHWESTERN GUINEA-BISSAU NEAR 
12N17W...TO 8N22W. THE ITCZ CONTINUES FROM 8N22W 5N30W 4N40W
AND 3N48W. ISOLATED AND DISORGANIZED RAINSHOWERS ARE TO THE 
SOUTH OF 10N TO THE EAST OF 60W. RAINSHOWERS ARE POSSIBLE
FROM 10N TO 12N BETWEEN 50W AND 60W...IN AN AREA OF DIRECTIONAL 
WIND SHEAR FROM THE MIDDLE LEVEL INTO THE UPPER LEVELS OF THE
ATMOSPHERE.

...DISCUSSION...

THE GULF OF MEXICO...

AN UPPER LEVEL RIDGE PASSES THROUGH THE BORDER OF THE UPPER 
TEXAS GULF COAST AND LOUISIANA BEYOND SOUTHEASTERN MEXICO AND 
GUATEMALA. SURFACE NORTHEASTERLY WIND FLOW COVERS THE AREA.
A SURFACE RIDGE PASSES THROUGH SOUTHWESTERN LOUISIANA AND THE 
UPPER TEXAS GULF COAST...TO THE DEEP SOUTH OF TEXAS...TO 
SOUTHERN MEXICO...CURVING THROUGH GUATEMALA AND SOUTH CENTRAL 
HONDURAS.  

THE CARIBBEAN SEA...

AN UPPER LEVEL INVERTED TROUGH IS ALONG 13N77W 7N79W. UPPER 
LEVEL SOUTHWESTERLY WIND FLOW MOVES OVER THE TOP OF THE INVERTED 
TROUGH. THE UPPER LEVEL SOUTHWESTERLY WIND FLOW IS PART OF 
LARGER-SCALE UPPER LEVEL ANTICYCLONIC WIND FLOW. AN UPPER LEVEL 
RIDGE EXTENDS FROM CENTRAL VENEZUELA...ACROSS NORTHERN COASTAL 
COLOMBIA...TOWARD THE NORTHWESTERN CORNER OF THE AREA. THE 
MONSOON TROUGH IS ALONG 10N76W AT THE COLOMBIA COAST TO 
10N80W...BEYOND 9N83W ALONG THE BORDER OF COSTA RICA AND PANAMA.
WIDELY SCATTERED MODERATE TO ISOLATED STRONG RAINSHOWERS ARE TO 
THE SOUTH OF 15N TO THE WEST OF 70W. 

THE ATLANTIC OCEAN...

A NORTH-TO-SOUTH SURFACE TROUGH SPANS FLORIDA. GALE-FORCE WINDS 
ARE OBSERVED TO THE NORTH OF 28N TO THE WEST OF 75W...WITH SEA 
HEIGHTS RANGING FROM 10 TO 12 FT IN NORTHEASTERLY SWELL.
MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW COVERS THE AREA
FROM 18N TO 30N BETWEEN 54W AND 73W. A SURFACE TROUGH IS ALONG
29N65W 20N66W. WIDELY SCATTERED TO SCATTERED MODERATE AND 
ISOLATED STRONG RAINSHOWERS ARE FROM 15N TO 20N BETWEEN 48W AND 
60W. ISOLATED TO WIDELY SCATTERED MODERATE RAINSHOWERS ARE FROM 
20N TO 25N BETWEEN 52W AND 56W. RAINSHOWERS ARE POSSIBLE FROM
25N TO 32N BETWEEN 56W AND 63W. SURFACE ANTICYCLONIC WIND FLOW
IS TO THE NORTH OF THE ITCZ TO THE EAST OF 55W...MOVING AROUND
A 1033 MB HIGH PRESSURE CENTER THAT IS NEAR 34N34W.

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

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