000
AXNT20 KNHC 241738
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN MAY 24 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...TROPICAL WAVES...
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 51W/52W TO THE SOUTH
10N MOVING WESTWARD 15 TO 20 KT. THIS WAVE IS ASSOCIATED WITH 
A MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE 
WATER PRODUCT FROM CIMSS AT 24/1630 UTC. THE LATEST VISIBLE 
SATELLITE IMAGERY SHOWS WHAT POSSIBLY IS THE AXIS ALONG 54W.
NO DEEP CONVECTIVE PRECIPITATION ACCOMPANIES THIS WAVE.
 
...THE ITCZ...
FROM THE COAST OF LIBERIA NEAR 6N10W TO 3N20W...CROSSING THE
EQUATOR NEAR 32W...INTO NORTHEASTERN BRAZIL NEAR 1S48W.
ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ARE
WITHIN 60 NM ON EITHER SIDE OF 3N AT THE PRIME MERIDIAN TO 2N10W
TO THE EQUATOR ALONG 18W. STRONG SHOWERS AND THUNDERSTORMS ARE
FROM 1N TO 2N BETWEEN 42W AND 46W.

...DISCUSSION...

THE GULF OF MEXICO AND THE ATLANTIC OCEAN TO THE WEST OF 70W... 
BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW COVERS THE AREA.
ONE SHORTWAVE TROUGH IS MOVING THROUGH SOUTH CENTRAL TEXAS AT 
THE MOMENT. A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION 
CENTER IS IN SOUTH CENTRAL ARKANSAS. THE GENERAL OVERALL PATTERN 
ON WATER VAPOR IMAGERY IS BROAD CYCLONIC FLOW. THIS CYCLONIC 
FLOW EVEN EXTENDS INTO THE NORTHWESTERN CORNER OF THE CARIBBEAN 
SEA...TO THE NORTH OF 17N TO THE WEST OF 80W. IT IS POSSIBLE 
THAT COMPARATIVELY SMALLER-SCALE TROUGHS AND CYCLONIC CENTERS 
MAY MOVE THROUGH THIS COMPARATIVELY LARGER-SCALE CYCLONIC AREA. 
ONE SURFACE TROUGH RUNS FROM THE UPPER TEXAS COAST TO THE LOWER 
RIO GRANDE VALLEY. A SECOND SURFACE TROUGH EXTENDS FROM 
SOUTHEASTERN LOUISIANA INTO THE NORTH CENTRAL GULF OF MEXICO. 
SHOWERS AND THUNDERSTORMS ARE IN THE GULF OF MEXICO TO THE NORTH 
OF 24N BETWEEN 85W AND 88W...AND TO THE NORTH OF 27N BETWEEN 92W 
AND 95W. SCATTERED MODERATE SHOWERS AND THUNDERSTORMS ARE IN AN 
AREA OF UPPER LEVEL DIFFLUENT FLOW WITHIN 75 NM ON EITHER SIDE 
OF THE LINE FROM 23N74W IN THE BAHAMA ISLANDS TO 27N78W IN THE 
NORTHERN BAHAMA ISLANDS...TO 32N81W NEAR THE BORDER OF GEORGIA 
AND SOUTH CAROLINA.
 
THE CARIBBEAN SEA...
THE NORTHWESTERN CORNER OF THE AREA...TO THE NORTH OF 17N TO THE 
WEST OF 80W...IS COVERED BY BROAD CYCLONIC FLOW ON WATER VAPOR 
IMAGERY. THE REST OF THE AREA IS UNDER THE INFLUENCE OF MIDDLE 
LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW...FROM WATER VAPOR 
IMAGERY AND FROM CIMSS-SATELLITE DERIVED WIND DATA AT
24/1500 UTC. THE SURFACE PRESSURE GRADIENT IS WEAK. THE SHOWERS 
AND THUNDERSTORMS TO THE NORTHEAST AND SOUTHWEST OF JAMAICA ARE
IN AN AREA OF UPPER LEVEL DIFFLUENT FLOW LEADING TO ENHANCED 
CONVECTIVE PRECIPITATION. THE PRECIPITATION THAT IS FROM 19N
TO 22N BETWEEN 60W AND 68W IS IN AN AREA OF BROAD CYCLONIC FLOW
ON THE WESTERN SIDE OF THE 31N46W 20N58W 17N59W WATER VAPOR 
LEVEL TROUGH.

THE ATLANTIC OCEAN...
A TROUGH ON WATER VAPOR IMAGERY PASSES THROUGH 31N46W TO 20N58W 
TO 17N59W. THIS FEATURE SUPPORTS THE CENTRAL ATLANTIC SURFACE 
TROUGH THAT EXTENDS FROM A 1019 MB LOW PRESSURE CENTER NEAR 
32N45W TO 30N44W 25N50W AND 20N65W. BROKEN TO OVERCAST 
MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION ARE WITHIN
150 NM ON EITHER SIDE OF 22N55W 25N46W 30N38W...AND FROM 30N TO
35N BETWEEN 30W AND 50W. ISOLATED MODERATE SHOWERS ARE OCCURRING
FROM 19N TO 22N BETWEEN 60W AND 68W. BROAD SURFACE ANTICYCLONIC
FLOW IS TO THE WEST OF THE 32N45W 20N65W SURFACE TROUGH. BROAD
UPPER LEVEL CYCLONIC FLOW IS TO THE NORTH OF 26N TO THE EAST
OF 30W.

$$
MT