000
AXNT20 KNHC 131745
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...THE ITCZ...

FROM THE COAST OF LIBERIA NEAR 6N10W TO 4N20W...CROSSING THE 
EQUATOR ALONG 23W TO 5S29W...TO 4S31W...INTO NORTHEASTERN BRAZIL
5S37W. SCATTERED MODERATE TO STRONG RAINSHOWERS AND THUNDERSTORMS
ARE FROM 6S TO 2N BETWEEN 29W AND 51W. ISOLATED MODERATE
RAINSHOWERS ARE FROM THE EQUATOR TO 7N BETWEEN 10W AND 25W. 
STRONG RAINSHOWERS AND THUNDERSTORMS ARE IN A FEW CLOUD CELLS 
FROM THE EQUATOR TO 2N BETWEEN 4W AND 6W.

...DISCUSSION...

FROM THE ATLANTIC OCEAN THAT IS TO THE WEST OF 70W
INTO THE GULF OF MEXICO...
THE DEEP LAYER TROUGH THAT HAS BEEN MOVING THROUGH THE U.S.A. 
DURING THE LAST FEW DAYS HAS MOVED OFF THE EAST COAST INTO THE
COASTAL WATERS OF THE ATLANTIC OCEAN. THE TROUGH PASSES THROUGH 
32N76W TOWARD ANDROS ISLAND IN THE BAHAMAS. THE TROUGH SUPPORTS 
A COLD FRONT THAT PASSES THROUGH 32N75W TO THE SOUTHEASTERN 
FLORIDA COAST ALONG 26N/27N...AND INTO THE EAST CENTRAL GULF OF 
MEXICO NEAR 25N86W. A STATIONARY FRONT CONTINUES FROM 25N86W TO
25N95W. ISOLATED MODERATE RAINSHOWERS ARE SPREAD ACROSS THE AREA 
OF THE ATLANTIC OCEAN FROM THE WATERS THAT ARE BETWEEN CUBA AND 
THE BAHAMAS NORTHWARD BEYOND 32N TO THE WEST OF 70W. 
PRECIPITATION IS POSSIBLE WITHIN 60 NM ON EITHER SIDE OF THE 
FRONTAL BOUNDARY FROM SOUTHEASTERN FLORIDA INTO THE GULF OF 
MEXICO.
  
THE CARIBBEAN SEA...
BROAD AND LARGE SCALE MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW 
COVERS THE CARIBBEAN SEA THANKS TO A TROUGH THAT PASSES OVER 
HISPANIOLA AND HEADS TOWARD THE SOUTHWESTERN CORNER OF THE AREA.
IT IS POSSIBLE THAT A BIT OF THE CYCLONIC FLOW THAT IS 
ASSOCIATED WITH THE ATLANTIC OCEAN-TO-GULF OF MEXICO TROUGH MAY
BE REINFORCING THE CYCLONIC FLOW THAT ALREADY HAS BEEN IN THE 
CARIBBEAN SEA FOR THE LAST FEW DAYS. A SURFACE TROUGH IS ALONG
17N70W 15N72W 13N72W. THIS TROUGH HAS BEEN DRIFTING WESTWARD 
DURING THE LAST FEW DAYS. THIS TROUGH FINALLY HAS MOVED AWAY 
FROM THE OVERCAST CLOUDS THAT ARE TO THE SOUTHEAST OF THE LINE 
THAT RUNS THROUGH 20N64W 15N70W 10N77W. RAINSHOWERS ARE POSSIBLE 
WITHIN 30 NM ON EITHER SIDE OF THE SURFACE TROUGH. SCATTERED 
STRONG RAINSHOWERS AND THUNDERSTORMS ARE FROM 11N TO 12N BETWEEN 
66W AND 68W...CLOSE TO THE ISLAS LOS ROQUES OF VENEZUELA.

THE REST OF THE ATLANTIC OCEAN TO THE EAST OF 70W...
BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW COVERS THE AREA 
THAT IS TO THE NORTH OF 20N BETWEEN 37W AND 54W. THIS CYCLONIC 
FLOW MOVES AROUND A BROAD CENTER THAT IS NEAR 28N46W.
A DISSIPATING STATIONARY FRONT PASSES THROUGH 32N45W TO
A 1015 MB LOW PRESSURE CENTER THAT IS NEAR 30N44W. A SURFACE
TROUGH CONTINUES FROM THE LOW CENTER TO 26N44W AND 23N49W.
RAINSHOWERS ARE POSSIBLE...SPREAD THROUGHOUT THE AREA THAT
IS TO THE NORTH OF 20N BETWEEN 30W AND 50W. ONE SURFACE RIDGE
IS ALONG 59W/60W FROM 21N BEYOND 32N. A SECOND SURFACE RIDGE
IS ALONG 15N34W TO 26N33W BEYOND 32N30W. UPPER LEVEL 
SOUTHWESTERLY WIND FLOW IS TO THE EAST OF THE LINE THAT EXTENDS 
FROM THE SOUTHERN CARIBBEAN SEA NEAR 10N77W TO NORTH OF PUERTO 
RICO ALONG 20N TO 27N54W. THIS FLOW ENDS UP MOVING RIGHT INTO 
THE AREA OF THE 28N46W CYCLONIC CIRCULATION CENTER.

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

$$
MT