000
AXNT20 KNHC 170527
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI APR 17 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 GOES-12 SATELLITE
IMAGERY THROUGH 0315 UTC...AND METEOSAT-9 IMAGERY THROUGH
0500 UTC. 

...THE ITCZ...
FROM 4N7W AT THE LIBERIA/IVORY COAST BORDER...CROSSING THE 
EQUATOR ALONG 12W TO 3S20W 3S37W...AND GOING INTO NORTHEASTERN 
BRAZIL NEAR 3S43W. STRONG SHOWERS AND THUNDERSTORMS ARE FROM THE 
EQUATOR TO 1.5N BETWEEN 48W AND 51W...FROM 1S TO 4N BETWEEN 5W 
AND 10W. ISOLATED AND DISORGANIZED MODERATE SHOWERS ARE TO THE 
SOUTH OF 2N ELSEWHERE TO THE EAST OF NORTHERN SOUTH AMERICA.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE LEVEL TO UPPER LEVEL SHORTWAVE TROUGH RUNS THROUGH 
CENTRAL TEXAS TO THE LOWER TEXAS COAST. A FEW CLUSTERS OF
STRONG SHOWERS AND THUNDERSTORMS ARE IN THE NORTH CENTRAL
GULF WATERS FROM 26N TO 29N BETWEEN 87W AND 93W. THIS 
PRECIPITATION IS OCCURRING IN AN AREA OF UPWARD VERTICAL
MOTION IN THE ATMOSPHERE IN A FAVORABLE SPOT FOR THE
DEVELOPMENT OF CONVECTIVE PRECIPITATION IN BETWEEN
TWO JET STREAMS.

THE CARIBBEAN SEA...
MIDDLE LEVEL TO UPPER LEVEL WESTERLY WIND FLOW MOVES FROM THE 
EASTERN PACIFIC OCEAN ACROSS CENTRAL AMERICA...FROM NICARAGUA
TO BELIZE...INTO THE WESTERN CARIBBEAN SEA AND BEYOND. UPPER
LEVEL SOUTHWESTERLY WIND FLOW MOVES INTO THE CARIBBEAN SEA 
ACROSS COSTA RICA AND PANAMA...AND FROM NORTHERN SOUTH AMERICA. 
BROAD LOW LEVEL CYCLONIC FLOW SPANS THE AREA.
 
THE ATLANTIC OCEAN...
A WESTERN ATLANTIC OCEAN DEEP LAYER TROUGH SUPPORTS THE COLD 
FRONT THAT PASSES THROUGH 32N61W TO 25N70W TO THE CENTRAL
BAHAMAS NEAR GREAT EXUMA AND LITTLE EXUMA. ISOLATED AND
DISORGANIZED MODERATE SHOWERS ARE WITHIN 20 NM TO 30 NM ON
EITHER SIDE OF 32N58W 28N65W 25N70W TO 23N76W. A SURFACE RIDGE
EXTENDS FROM 28N20W TO A 1026 MB HIGH PRESSURE CENTER NEAR
26N33W TO 25N46W 23N58W TO 22N68W. A MIDDLE LEVEL CYCLONIC
CIRCULATION CENTER IS NEAR 18N31W. A TROUGH IS ALONG 20N30W
18N31W 14N38W. BROAD LARGE SCALE UPPER LEVEL ANTICYCLONIC
FLOW COVERS THE AREA TO THE EAST OF 50W.

$$
MT