000
AXNT20 KNHC 241056
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON AUG 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...SPECIAL FEATURES...
HURRICANE BILL LOST ITS TROPICAL CHARACTERISTICS AND IT WAS 
DOWNGRADED TO AN EXTRATROPICAL STORM AT 24/0900 UTC. THE CENTER 
OF EXTRATROPICAL STORM BILL AT 24/0900 UTC IS NEAR 48.6N 50.2W  
OR ABOUT 190 MILES/305 KM TO THE NORTHEAST OF CAPE RACE 
NEWFOUNDLAND. BILL IS MOVING TOWARD THE EAST-NORTHEAST 37 KT. 
THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 980 MB. THE MAXIMUM 
SUSTAINED WIND SPEEDS ARE 60 KT WITH GUSTS TO 75 KT. PLEASE READ 
THE FORECAST/ADVISORY UNDER AFOS/WMO HEADERS TCMAT3/WTNT23 KNHC 
AND THE PUBLIC ADVISORY UNDER TCPAT3/WTNT33 KNHC FOR MORE 
DETAILS. 

..TROPICAL WAVES...
AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 25W/26W TO THE 
SOUTH OF 20N MOVING WEST 15 TO 20 KT. ISOLATED MODERATE SHOWERS
FROM 10N TO 17N BETWEEN 25W AND 30W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 55W/56W TO THE SOUTH OF 
23N...NOT MOVING MUCH DURING THE LAST SIX HOURS. IT HAD BEEN
MOVING WEST ABOUT 20 KT. SCATTERED MODERATE SHOWERS TO ISOLATED 
STRONG THUNDERSTORMS FROM 14N TO 20N BETWEEN 50W AND 60W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 73W TO THE SOUTH OF 18N 
MOVING WEST 15 TO 20 KT. DISORGANIZED ISOLATED MODERATE SHOWERS 
AND THUNDERSTORMS ARE FROM 11N TO 15N BETWEEN 69W AND 77W.

THE ITCZ...
FROM 14N17W TO 10N30W TO 9N53W BEYOND SOUTHERN TRINIDAD.  
ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS
ELSEWHERE FROM 6N TO 16N BETWEEN AFRICA AND SOUTH AMERICA.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL TROUGH PASSES THROUGH CENTRAL ALABAMA TO THE 
NORTH CENTRAL GULF...INTO THE SOUTHWESTERN CORNER OF THE AREA
TO INLAND MEXICO ABOUT 180 NM TO THE WEST OF THE ISTHMUS OF 
TEHUANTEPEC. THIS TROUGH IS GUIDING THE CURRENT GULF OF MEXICO 
STATIONARY FRONT THAT STRETCHES FROM CENTRAL FLORIDA INTO THE 
CENTRAL GULF...AND THEN IT CURVES NORTHWARD BEYOND EAST TEXAS. 
DISORGANIZED ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS
ARE EVERYWHERE.
 
THE CARIBBEAN SEA...
BROAD UPPER LEVEL CYCLONIC FLOW HAS INVADED THE AREA TO THE 
NORTH OF 14N TO THE EAST OF 70W...FROM A LARGE-SCALE ATLANTIC 
OCEAN 26N62W CYCLONIC CIRCULATION CENTER. THE UPPER LEVEL FLOW 
TO THE SOUTH OF 14N TO THE EAST OF 70W FROM THE EAST AND 
SOUTHEAST...CREATING A LITTLE BIT OF UPPER LEVEL DIFFLUENT 
FLOW...AND A FEW SHOWERS IN THIS AREA. A MIDDLE LEVEL TO UPPER 
LEVEL INVERTED TROUGH HAS MOVED ASHORE FROM HONDURAS TO 
NICARAGUA TO COSTA RICA. THIS TROUGH HAS BEEN SPREADING ISOLATED 
MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS WITH IT...FROM
NICARAGUA TO HONDURAS...EL SALVADOR...AND BELIZE.

THE ATLANTIC OCEAN...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH GOES FROM A 34N50W CYCLONIC 
CIRCULATION CENTER TO A SECOND CYCLONIC CENTER THAT IS NEAR 
26N62W. CYCLONIC FLOW THAT IS AROUND THE 26N62W CENTER COVERS 
THE AREA FROM 14N TO THE EAST OF 70W IN THE CARIBBEAN SEA TO 34N 
BETWEEN 50W AND 70W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG 
THUNDERSTORMS ARE WITHIN THE AREA OF CYCLONIC FLOW OF THE 26N62W 
CENTER. A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM
A 28N29W CYCLONIC CENTER TO 18N35W TO 10N38W.

$$
MT