000
AXNT20 KNHC 250604
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE AUG 25 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.

...SPECIAL FEATURES...
A TROPICAL WAVE IS ALONG 24N63W IN THE ATLANTIC OCEAN...ACROSS
SAINT KITTS AND NEVIS TO 11N62W IN THE SOUTHEASTERN CORNER OF
THE CARIBBEAN SEA...REPORTEDLY MOVING WESTWARD ABOUT 20 KT.
THIS WAVE IS MOVING THROUGH THE AREA OF AN ALREADY-EXISTING
MIDDLE LEVEL TO UPPER LEVEL TROUGH. THE PRE-EXISTING TROUGH
GOES FROM A CYCLONIC CENTER NEAR 35N54W 32N62W 26N67W 20N68W
TO 16N73W IN THE CARIBBEAN SEA. NUMEROUS STRONG SHOWERS AND 
THUNDERSTORMS FROM 18N TO 22N BETWEEN 56W AND 61W IN 
PRECIPITATION THAT HAS FORMED IN UPPER LEVEL DIFFLUENT FLOW.
STRONG SHOWERS AND THUNDERSTORMS ALSO COVER THE WATERS FROM
23N TO 24N BETWEEN 64W AND 66W. ISOLATED AND DISORGANIZED
SHOWERS COVER THE AREA FROM 14N TO 20N BETWEEN 60W AND 67W.
OTHER ISOLATED AND DISORGANIZED MODERATE SHOWERS COVER THE
ATLANTIC OCEAN ELSEWHERE TO THE NORTH OF 20N BETWEEN 60W AND
74W.

..TROPICAL WAVES...
AN EASTERN ATLANTIC OCEAN TROPICAL WAVE RUNS FROM 19N31W TO
A 1011 MB LOW PRESSURE CENTER NEAR 13N32W TO 8N32W. THIS WAVE
IS MOVING WESTWARD ABOUT 15 KT. A MIDDLE LEVEL TO UPPER LEVEL 
TROUGH THAT IS ON TOP OF AND JUST TO THE WEST OF THIS WAVE GOES
FROM 30N30W TO A 26N34W CYCLONIC CIRCULATION CENTER TO 17N36W 
11N36W. ISOLATED MODERATE SHOWERS ARE WITHIN 120 NM ON EITHER
SIDE OF 24N25W 17N28W 12N33W 9N36W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 80W/81W TO THE SOUTH OF
18N MOVING WEST 15 TO 20 KT. A 1006 MB LOW PRESSURE CENTER IS
ALONG THIS WAVE NEAR 11N. NUMEROUS STRONG SHOWERS AND 
THUNDERSTORMS ARE FROM 11N TO 13N BETWEEN 82W AND 84W.
ISOLATED MODERATE SHOWERS COVER THE AREA FROM 13N TO 15N
BETWEEN 80W AND 84W.

THE ITCZ...
FROM 14N17W TO 14N30W TO 8N47W TO 11N60W. ISOLATED MODERATE
SHOWERS TO LOCALLY STRONG THUNDERSTORMS FROM 8N TO 9N
BETWEEN 40W AND 42W.

...DISCUSSION...

THE GULF OF MEXICO...
THE UPPER LEVEL TROUGH THAT HAS BEEN COVERING THE SOUTH CENTRAL 
GULF OF MEXICO HAS BEEN ERODED AWAY BY UPPER LEVEL SOUTHWESTERLY 
WIND FLOW. THE SAME TROUGH NOW PASSES THROUGH MISSISSIPPI TO 
NORTHEASTERN MEXICO JUST TO THE SOUTH OF THE DEEP SOUTH OF TEXAS 
INTO CENTRAL INTERIOR MEXICO. A STATIONARY FRONT LINGERS FROM
30N80W TO NORTH CENTRAL FLORIDA TO THE SOUTH CENTRAL GULF OF 
MEXICO INTO THE SOUTHWESTERN CORNER OF THE AREA NEAR 21N95W.
SURFACE HIGH PRESSURE HAS BUILT FROM THE NORTH CENTRAL GULF OF
MEXICO SOUTHWARD. STRONG SHOWERS AND THUNDERSTORMS COVER THE 
AREA FROM THE ISTHMUS OF TEHUANTEPEC EASTWARD TO NORTHWESTERN
GUATEMALA...AS A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH 
MOVES FROM THE NORTHWESTERN CARIBBEAN SEA...ACROSS CENTRAL 
AMERICA TO BELIZE...GUATEMALA...AND MEXICO.
 
THE CARIBBEAN SEA...
BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW COVERS THE AREA 
TO THE NORTH OF 15N TO THE EAST OF 80W. THIS CYCLONIC FLOW IS 
ASSOCIATED WITH THE TROUGH THAT IS ON TOP OF AND TO THE WEST OF 
THE 24N63W 11N62W TROPICAL WAVE. ISOLATED MODERATE SHOWERS ARE 
POSSIBLE IN THE AREA OF CYCLONIC FLOW. STRONG SHOWERS AND 
THUNDERSTORMS ARE IN THE SOUTHWESTERN CORNER WITH THE 80W/81W
TROPICAL WAVE.

THE ATLANTIC OCEAN...
THE MIDDLE LEVEL TO UPPER LEVEL TROUGH GOES FROM A CYCLONIC 
CENTER NEAR 35N54W TO 32N62W 26N67W 20N68W...AND TO 16N73W
IN THE CARIBBEAN SEA. THIS TROUGH IS NEAR THE 24N63W 11N62W 
TROPICAL WAVE. A SECOND TROUGH RUNS FROM 30N30W TO 11N36W.
THIS TROUGH IS NEAR THE 19N31W 8N32W TROPICAL WAVE.

$$
MT