000
AXNT20 KNHC 200602
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT WED MAY 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0515 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 56W/57W TO THE SOUTH OF 9N MOVING WEST 
ABOUT 10 KT. THIS POSITION COINCIDES WITH HIGHER LEVELS OF 
PRECIPITABLE WATER ON THE MIMIC-TPW PRODUCT FROM CIMSS AS LATE 
AS 20/0545 UTC. THE WAVE IS MOVING UNDER AN AREA OF MIDDLE TO 
UPPER LEVEL ANTICYCLONIC FLOW. EXPECT SCATTERED SHOWER ACTIVITY 
OVER THE GUYANAS AND EASTERN VENEZUELA DURING THE NEXT FEW DAYS.
ISOLATED MODERATE SHOWERS...SOME WEAKENING AND DISSIPATING AT 
TIMES...ARE FROM THE EQUATOR TO 10N BETWEEN 57W AND 60W.

...THE ITCZ...

FROM LIBERIA NEAR 7N10W...CROSSING THE EQUATOR ALONG 21W...
TO 3S30W TO 5S45W. ISOLATED STRONG SHOWERS AND POSSIBLE 
THUNDERSTORMS ARE FROM THE EQUATOR TO 1N BETWEEN 5W AND 7W...
AND FROM THE EQUATOR TO 5N BETWEEN 14W AND 20W.
ISOLATED AND DISORGANIZED MODERATE SHOWERS ARE 
ELSEWHERE TO THE SOUTH OF 4N.

...DISCUSSION...

THE GULF OF MEXICO...THE NORTHWESTERN CARIBBEAN SEA...AND
THE ATLANTIC OCEAN TO THE WEST OF 70W...
THE DEEP LAYER TROUGH FROM 24 HOURS AGO THAT WAS SUPPORTING THE 
COLD FRONT HAS IT MOVED ACROSS THE AREA HAS INTENSIFIED TO THE 
SOUTH...EXTENDING ITSELF INTO THE NORTHWESTERN CORNER OF THE 
CARIBBEAN SEA. THE TROUGH NOW IS ALONG THE LINE FROM 
SOUTHEASTERN GEORGIA TO A CYCLONIC CIRCULATION CENTER THAT IS
ABOUT 75 NM TO THE NORTHWEST OF KEY WEST FLORIDA...TO THE COAST
OF HONDURAS NEAR 85W. MIDDLE LEVEL TO UPPER LEVEL DRY AIR IS
MOVING ACROSS THE GULF OF MEXICO FROM TEXAS TO THE EAST OF 100W
AND LOUISIANA...THROUGH THE NORTHWESTERN CORNER OF THE AREA...
ACROSS THE CENTRAL GULF WATERS AND THROUGH THE YUCATAN CHANNEL
INTO THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA TO THE NORTH 
OF HONDURAS TO THE WEST OF 80W. HIGH CLOUDS ARE BEING PUSHED TO 
THE EAST UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE THAT IS IN 
CENTRAL MEXICO. BROAD LARGE-SCALE CYCLONIC FLOW ON THE WATER 
VAPOR SATELLITE IMAGERY COVERS THE AREA FROM 15N TO 33N BETWEEN 
70W AND 91W...COVERING PARTS OF THE ATLANTIC OCEAN...THE GULF OF 
MEXICO...AND THE CARIBBEAN SEA. STRONG SHOWERS AND THUNDERSTORMS 
ARE IN INDIVIDUAL CELLS FROM EXTREME SOUTHEASTERN CUBA TO THE 
SOUTHEASTERN BAHAMA ISLANDS...FROM 23N TO 28N BETWEEN 72W AND 
76W...AND ALONG THE NORTHEASTERN COAST OF FLORIDA IN BETWEEN 
DAYTONA BEACH AND TITUSVILLE. THE COMPARATIVELY STRONGEST 
SHOWERS AND THUNDERSTORMS ARE WITHIN A 30 NM RADIUS OF
21.5N71W JUST TO THE EAST OF THE TURKS ISLANDS. ISOLATED 
MODERATE SHOWERS ALSO ARE IN THE GULF OF MEXICO FROM 25N TO
27N BETWEEN 83W AND 85W. A 1007 MB LOW PRESSURE CENTER IS OVER
WATER JUST TO THE WEST OF THE EVERGLADES IN SOUTHWESTERN 
FLORIDA. A TROUGH EXTENDS FROM THIS LOW CENTER...ACROSS CUBA
TO 18N81W IN THE NORTHWESTERN CARIBBEAN SEA. A SECOND SURFACE 
TROUGH SPANS THE BAHAMA ISLANDS. 

THE REST OF THE CARIBBEAN SEA...
BROAD AND GENERAL WESTERLY WIND FLOW COVERS THE AREA.
AN UPPER LEVEL TROUGH CUTS THROUGH THE EASTERN CARIBBEAN SEA 
ALONG 63W/64W REACHING ITS BASE IN NORTHERN VENEZUELA. UPPER 
LEVEL ANTICYCLONIC FLOW MOVES AWAY FROM VENEZUELA...ACROSS THE
EXTREME SOUTHEASTERN CORNER OF THE AREA...INTO THE OPEN WATERS 
OF THE ATLANTIC OCEAN BEYOND 23N48W.

THE ATLANTIC OCEAN TO THE EAST OF 70W...
A PERSISTENT DEEP LAYER CYCLONIC CIRCULATION CENTER IS NEAR 
31N52W ON WATER VAPOR SATELLITE IMAGERY. A 1016 MB LOW PRESSURE 
CENTER IS NEAR 30N55W AT THE SURFACE. BROAD CYCLONIC FLOW ON
WATER VAPOR IMAGERY COVERS THE ATLANTIC OCEAN FROM 23N TO 37N
BETWEEN 40W AND 65W. A SURFACE TROUGH REMAINS ALONG 27N46W
23N50W 21N57W 21N62W. ISOLATED MODERATE SHOWERS ARE WITHIN
30 NM ON EITHER SIDE OF 23N50W 27N43W 30N43W CURVING TO
33N50W...AND FROM 29N TO 33N BETWEEN 50W AND 55W. A MIDDLE
LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N27W TO 28N30W. 
THIS TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 33N40W
TO 34N48W.

$$
MT