000
AXNT20 KNHC 130605
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT THU MAY 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0515 UTC.

...THE ITCZ...

FROM SOUTHERN COASTAL SIERRA LEONE TO 4N20W 2N30W 2N40W 2N47W...
INTO EXTREME NORTHEASTERN BRAZIL NEAR 1N51W. SCATTERED TO 
NUMEROUS STRONG RAINSHOWERS AND THUNDERSTORMS ARE FROM 6N TO 8N 
BETWEEN 13W AND 15W. SCATTERED MODERATE RAINSHOWERS TO ISOLATED 
STRONG THUNDERSTORMS ARE IN THE ATLANTIC OCEAN TO THE SOUTH OF 
6N BETWEEN 20W AND 50W.

...DISCUSSION...

THE GULF OF MEXICO...
CYCLONIC FLOW FROM A DEEP LAYER TROUGH SPANS THE U.S.A. MIDWEST
BETWEEN ILLINOIS AND COLORADO. THE TROUGH SUPPORTS A CENTRAL 
U.S.A. FRONTAL BOUNDARY...THAT IS FORECAST TO REACH THE TEXAS 
GULF COAST DURING THE NEXT 24 HOURS OR SO. UPPER LEVEL
ANTICYCLONIC WIND FLOW MOVES FROM THE EASTERN PACIFIC OCEAN AREA 
FROM 10N TO 30N BETWEEN 100W AND 120W...ACROSS MEXICO AND PARTS 
OF CENTRAL AMERICA INTO THE GULF OF MEXICO AND THE ADJACENT 
CARIBBEAN SEA. BROAD UPPER LEVEL WESTERLY AND NORTHWESTERLY FLOW 
COVERS THE GULF OF MEXICO. BROAD MIDDLE LEVEL TO UPPER LEVEL 
CYCLONIC FLOW THAT IS RELATED TO AN ATLANTIC OCEAN TROUGH COVERS 
FLORIDA. BROAD SURFACE ANTICYCLONIC FLOW COVERS THE AREA THAT 
IS TO THE NORTH OF 25N TO THE EAST OF 90W...MOVING AROUND
A 1015 MB HIGH PRESSURE CENTER THAT IS NEAR 28N84W. MODERATE TO 
STRONG RAINSHOWERS AND THUNDERSTORMS COVER THE GULF OF MEXICO
FROM 24N TO LOUISIANA BETWEEN 90W AND 94W. THIS PRECIPITATION
IS ASSOCIATED WITH A SQUALL LINE THAT EXTENDS FROM SOUTHWESTERN
LOUISIANA TO NORTHEASTERN MEXICO JUST TO THE SOUTH OF THE TEXAS
BORDER.

THE CARIBBEAN SEA...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 23N74W IN 
THE BAHAMAS...ACROSS EASTERN CUBA AND JAMAICA TO 13N79W IN THE 
SOUTHWESTERN CORNER OF THE AREA. ISOLATED MODERATE RAINSHOWERS 
TO POSSIBLE THUNDERSTORMS COVER THE AREA FROM NORTHWESTERN 
NICARAGUA TO NORTHWESTERN GUATEMALA...IN BROAD SURFACE LOW 
PRESSURE AND UPPER LEVEL ANTICYCLONIC FLOW. RAINSHOWERS AND 
THUNDERSTORMS ARE IN COLOMBIA...NORTHWESTERN VENEZUELA...AND 
PANAMA AND SURROUNDING COASTAL WATERS FROM 6N TO 12N BETWEEN 69W 
AND 82W...IN BROAD MONSOONAL CYCLONIC FLOW. THE SURFACE PRESSURE 
GRADIENT IS WEAK ACROSS THE AREA. A SURFACE TROUGH EXTENDS FROM 
PUERTO RICO TO 17N70W 14N72W AND COASTAL COLOMBIA NEAR 11N73W.
BROKEN TO OVERCAST MULTILAYERED CLOUDS ARE TO THE EAST OF 70W.
RAINSHOWERS AND POSSIBLE THUNDERSTORMS ARE TO THE NORTH OF 15N
TO THE EAST OF 70W.

THE ATLANTIC OCEAN...
BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW COVERS THE AREA 
TO THE WEST OF 50W. IT IS POSSIBLE THAT MULTIPLE CYCLONIC 
CIRCULATION CENTERS ARE EMBEDDED IN THE LARGER-SCALE CYCLONIC 
FLOW...REALLY ONLY TO THE NORTH OF 30N TO THE WEST OF 50W.
A 995 MB LOW PRESSURE CENTER IS NEAR 36N62W. A DISSIPATING
COLD FRONT EVENTUALLY EXTENDS FROM THE CYCLONIC ENVELOPE AND IT 
REACHES 31N47W. A DISSIPATING STATIONARY FRONT CONTINUES FROM 
31N47W TO 25N50W. A SURFACE TROUGH CONTINUES FROM 25N50W TO 
23N53W AND 21N59W. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 
32N46W 25N60W 22N72W 31N79W...AND ELSEWHERE TO THE NORTHWEST OF
30N38W 19N50W 14N60W. BROAD SURFACE ANTICYCLONIC FLOW IS TO THE 
NORTH OF 10N BETWEEN AFRICA AND THE DISSIPATING FRONTAL 
BOUNDARIES. BROAD UPPER LEVEL CYCLONIC FLOW IS TO THE NORTH OF 
14N TO THE EAST OF 30W.

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

$$

MT