000
AXNT20 KNHC 071055
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT THU APR 07 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 THE LIBERIA COAST NEAR 6N11W TO 5N15W...CROSSING THE 
EQUATOR ALONG 24W...TO 1S39W. NUMEROUS STRONG RAINSHOWERS AND 
THUNDERSTORMS ARE FROM 1N TO 4N BETWEEN 22W AND 30W...FROM
2N TO 3N BETWEEN 39W AND 41W...AND FROM THE EQUATOR TO 3N
BETWEEN 45W AND 51W. ISOLATED MODERATE RAINSHOWERS TO LOCALLY 
STRONG THUNDERSTORMS ARE ELSEWHERE TO THE SOUTH OF 6N BETWEEN 
15W AND 53W.

...DISCUSSION...

THE GULF OF MEXICO...
BROAD MIDDLE LEVEL TO UPPER LEVEL WESTERLY WIND FLOW SPANS THE 
AREA. SOME OF THE UPPER LEVEL FLOW BECOMES NORTHWESTERLY AS IT
MOVES TOWARD THE SOUTHEASTERN CORNER OF THE GULF OF MEXICO 
TOWARD CUBA. THE SURFACE WIND PATTERN CONSISTS OF A BROAD RIDGE
THAT EXTENDS FROM A 1023 MB ATLANTIC OCEAN HIGH PRESSURE CENTER 
THAT IS NEAR 33N69W TO SOUTHERN FLORIDA...TOWARD THE GULF OF 
HONDURAS IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA. THE 
FRONTAL BOUNDARIES THAT WERE APPARENT AT 07/0300 UTC AND
07/0600 UTC HAVE WEAKENED BY 07/0900 UTC. SCATTERED TO BROKEN 
LOW LEVEL TO MIDDLE LEVEL CLOUDS ARE TO THE NORTH OF 24N84W 
26N96W.

THE CARIBBEAN SEA...
BROAD UPPER LEVEL ANTICYCLONIC FLOW SPANS THE ENTIRE AREA.
THE MIDDLE LEVEL TO LOW LEVEL WIND FLOW HAS A DEFINITE EASTERLY 
COMPONENT. SCATTERED MODERATE TO STRONG RAINSHOWERS AND 
THUNDERSTORMS COVER THE AREA FROM COLOMBIA TO THE WATERS THAT 
ARE JUST TO THE NORTH OF PANAMA FROM 6N TO 10N BETWEEN 74W AND 
81W...IN THE AREA OF A MIDDLE LEVEL TROUGH. POSSIBLE RAINSHOWERS 
ELSEWHERE ARE SPREAD ACROSS THE AREA THAT IS TO THE SOUTH OF 20N
TO THE EAST OF 83W...IN CLUSTERS OF LOW CLOUDS THAT ARE MOVING 
WESTWARD WITH THE TRADEWIND FLOW.

THE ATLANTIC OCEAN...
AN ATLANTIC OCEAN COLD FRONT PASSES THROUGH 32N55W TO 28N60W
27N64W 26N71W...AND WEAKENING FROM 26N71W TO 23N78W ACROSS THE 
CENTRAL BAHAMAS. THE UPPER LEVEL SUPPORT FOR THIS FRONT IS ALONG 
AND TO THE NORTH OF 31N/32N BETWEEN 48W AND 60W. RAINSHOWERS ARE 
POSSIBLE WITHIN 45 NM ON EITHER SIDE OF THE FRONTAL BOUNDARY.
A DEEP LAYER TROUGH PASSES THROUGH 33N24W TO 20N28W TO 12N47W.
THIS TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N21W TO
23N27W AND 21N32W. THE FRONT IS COMPARATIVELY WEAKER FROM 21N32W
TO 18N42W TO 17N54W AND 20N62W. SOME OF THE COMPUTER MODELS HAVE 
BEEN FORECASTING THE COMPARATIVELY WEAKER PART OF THE FRONT TO 
MOVE ACROSS PARTS OF THE NORTHEASTERN CARIBBEAN SEA DURING THE
NEXT 24 HOURS OR SO...BRINGING SOME PRECIPITATION TO THAT AREA.
RAINSHOWERS ARE POSSIBLE WITHIN 90 NM ON EITHER SIDE OF THE LINE 
THAT PASSES THROUGH 32N20W 25N25W 20N35W 17N50W 16N56W 21N61W.
SURFACE ANTICYCLONIC FLOW COVERS THE ATLANTIC OCEAN BETWEEN THE 
TWO FRONTAL BOUNDARIES. A RIDGE PASSES THROUGH 32N43W TO 25N54W 
AND 23N65W.

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

$$
MT