000
AXNT20 KNHC 132355
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 PM EDT WED APR 13 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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...

THE ITCZ AXIS IS CENTERED ALONG 6N10W 5N20W 2N30W EQ33W 3S40W. 
SCATTERED MODERATE TO STRONG CONVECTION IS S OF THE IVORY COAST 
FROM EQ-2N BETWEEN 4W-7W. ISOLATED MODERATE CONVECTION IS FROM 
2N-5N BETWEEN 19W-27W. WIDELY SCATTERED MODERATE CONVECTION IS 
FROM 1N-5S BETWEEN 20W-50W. 

...DISCUSSION...

THE GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT EXTENDS FROM S FLORIDA TO THE 
CENTRAL GULF OF MEXICO ALONG 25N80W 24N85W 26N90W. THE FRONT IS 
NOW MOSTLY VOID OF ANY PRECIPITATION. A 1018 MB HIGH HAS 
DEVELOPED S OF MISSISSIPPI NEAR 29N87W PRODUCING FAIR WEATHER.  
5-10 KT ANTICYCLONIC SURFACE WINDS ARE OVER THE NE GULF. 5-10 KT 
SE WINDS ARE OVER THE REMAINDER OF THE GULF. VERY SLIGHT COOLING 
IS NOTED N OF THE FRONT. IN THE UPPER LEVELS...A TROUGH IS OVER 
THE E GULF E OF 88W SUPPORTING THE SURFACE FRONT. AN UPPER LEVEL 
HIGH IS CENTERED OVER S MEXICO NEAR 20N101W PRODUCING 
ANTICYCLONIC UPPER WINDS W OF 88W. STRONG SUBSIDENCE IS OVER THE 
GULF WITH ISOLATED HIGH CLOUDS ONLY OVER THE NW GULF. 
EXPECT...THE FRONT TO DISSIPATE OVER THE NEXT 24 HOURS... AND 
FOR ONSHORE SURFACE FLOW TO PRODUCE SCATTERED SHOWERS OVER E 
TEXAS AND S LOUISIANA.   

THE CARIBBEAN SEA...
A SURFACE TROUGH IS OVER THE CENTRAL CARIBBEAN EXTENDING FROM 
LAKE MARACAIBO VENEZUELA TO S OF HISPANIOLA NEAR 16N71W. 
SCATTERED SHOWERS ARE OVER THE E CARIBBEAN E OF 70W. RADAR 
IMAGERY FROM PUERTO RICO CONFIRMS THE PRECIPITATION N OF 15N AND 
E OF 69W. MOSTLY FAIR WEATHER IS W OF 70W EXCEPT FOR SOME 
SHOWERS OVER JAMAICA AND INLAND COSTA RICA. IN THE UPPER 
LEVELS... AN UPPER LEVEL TROUGH IS OVER THE CARIBBEAN WITH AXIS 
FROM THE WINDWARD PASSAGE TO PANAMA. STRONG SUBSIDENCE IS W OF 
70W...WITH SIGNIFICANT UPPER LEVEL MOISTURE AND OVERCAST HIGH 
CLOUDS OVER THE E CARIBBEAN E OF 70W. EXPECT LITTLE CHANGE OVER 
THE NEXT 24 HOURS OTHER THAN THE SURFACE TROUGH MOVING W. 

THE ATLANTIC OCEAN...
A COLD FRONT IS OVER THE W ATLANTIC FROM 32N73W TO S FLORIDA AT 
25N80W. THE FRONT IS MOSTLY VOID OF ANY PRECIPITATION. A 1026 MB 
HIGH IS OVER THE CENTRAL ATLANTIC NEAR 35N57W. A 1013 MB LOW IS 
ALSO OVER THE CENTRAL ATLANTIC NEAR 29N43W MOVING SE. A SURFACE 
TROUGH EXTENDS S OF THE LOW ALONG 27N41W 23N43W 22N46W. 
SCATTERED SHOWERS ARE WITHIN 90 NM E OF THE TROUGH. A SHEAR AXIS 
CONTINUES W TO 21N58W. IN THE TROPICS...SCATTERED SHOWERS WITH 
OVERCAST MULTILAYERED CLOUDS ARE E OF THE LESSER ANTILLES FROM 
11N-22N BETWEEN 50W-60W. IN THE UPPER LEVELS A TROUGH IS W OF 
60W SUPPORTING THE SURFACE FRONT. AN UPPER LEVEL LOW IS ALSO 
CENTERED OVER THE CENTRAL ATLANTIC NEAR 30N43W SUPPORTING THE 
CENTRAL ATLANTIC SURFACE LOW. EXPECT...THE W ATLANTIC FRONT TO 
MOVE E OVER THE NEXT 24 HOURS. EXPECT THE SURFACE LOW TO MOVE SE 
TO 24N35W WITH SHOWERS. ALSO EXPECT THE SHOWERS E OF THE LESSER 
ANTILLES TO CONTINUE.   

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

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FORMOSA