000
AXNT20 KNHC 201106
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT WED APR 20 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC. 

...THE ITCZ...

FROM LIBERIA NEAR 5N9W TO 2N20W...CROSSING THE EQUATOR ALONG 
27W..TO THE NORTHEASTERN BRAZIL COAST NEAR 4S40W. STRONG 
RAINSHOWERS AND THUNDERSTORMS ARE FROM 1S TO 5N BETWEEN 15W
AND 24W. ISOLATED MODERATE RAINSHOWERS TO LOCALLY STRONG
THUNDERSTORMS ARE FROM 7N TO THE BRAZIL COAST BETWEEN 
39W AND 54W.

...DISCUSSION...

THE GULF OF MEXICO...
MIDDLE LEVEL TO UPPER LEVEL WESTERLY WIND FLOW SPANS THE AREA. 
OVERCAST LOW CLOUDS AND HAZE ARE IN THE GULF COASTAL PLAINS FROM 
THE MIDDLE TEXAS COAST TO TALLAHASSEE FLORIDA. SOME VISIBILITIES
IN THIS AREA EVEN HAVE BEEN OBSERVED TO BE LESS THAN 3 MILES.
BROAD AND WEAK UPPER CYCLONIC FLOW COVERS THE AREA FROM THE 
YUCATAN PENINSULA TO 26N BETWEEN 86W AND 90W. SOUTHERLY RETURN 
FLOW WINDS RANGING FROM 20 TO 25 KT COVER MUCH OF THE AREA. THE 
SURFACE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE THAT IS IN
THE EASTERN GULF OF MEXICO AND THE LOW PRESSURE THAT IS IN THE 
U.S.A. CENTRAL PLAINS AND NORTHEASTERN MEXICO WILL RESULT IN
FRESH TO STRONG SOUTHEASTERLY WINDS ACROSS MUCH OF THE WESTERN
GULF OF MEXICO THROUGH SUNDAY.

THE CARIBBEAN SEA...
BROAD UPPER LEVEL SOUTHERLY-TO-SOUTHWESTERLY WIND FLOW COVERS 
THE AREA TO THE SOUTH OF THE LINE FROM PUERTO RICO TO EASTERN 
HONDURAS. BROAD UPPER LEVEL WESTERLY TO SOUTHWESTERLY WIND FLOW 
SPANS THE REST OF THE AREA. RAINSHOWERS ARE POSSIBLE IN SMALL 
CLUSTERS OF LOW CLOUDS IN MOST AREAS...EXCEPT FOR THE AREA
THAT IS TO THE SOUTH OF 13N BETWEEN 65W AND 80W.

THE ATLANTIC OCEAN...
BROAD UPPER LEVEL CYCLONIC FLOW COVERS THE ATLANTIC OCEAN
TO THE NORTH OF 20N BETWEEN 52W AND THE BAHAMAS. A SURFACE 
TROUGH IS ALONG 27N60W...TO A 1012 MB LOW PRESSURE CENTER THAT 
IS NEAR 22N59W...TO 18N59W. SCATTERED MODERATE RAINSHOWERS TO 
ISOLATED STRONG THUNDERSTORMS ARE FROM 22N TO 28N BETWEEN 53W 
AND 60W. ISOLATED MODERATE RAINSHOWERS COVER THE WATERS FROM 20N 
TO 30N BETWEEN 60W AND THE BAHAMAS. AN UPPER LEVEL TROUGH PASSES 
OVER THE MADEIRA ARCHIPELAGO TO 26N23W 18N31W AND 13N40W. THE 
SOUTHERNMOST POINT OF A COLD FRONT REACHES 31N14W. A SURFACE 
TROUGH CONTINUES FROM 31N14W TO 25N20W AND 19N27W. RAINSHOWERS 
ARE POSSIBLE WITHIN 30 TO 60 NM ON EITHER SIDE OF 26N23W 28N18W
BEYOND 32N12W. BROAD SURFACE ANTICYCLONIC FLOW COVERS THE AREA
TO THE NORTH OF 16N BETWEEN THE SURFACE TROUGHS.

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

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MT