000
AXNT20 KNHC 231049
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN AUG 23 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...
THE CENTER OF HURRICANE BILL AT 23/0900 UTC IS NEAR 41.2N 66.5W 
OR ABOUT 185 MILES/300 KM TO THE EAST OF NANTUCKET 
MASSACHUSETTS...AND ABOUT 275 MILES/445 KM TO THE 
SOUTH-SOUTHWEST OF HALIFAX NOVA SCOTIA. BILL IS MOVING TOWARD
THE NORTH-NORTHEAST 23 KT. THE ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 961 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 75 KT 
WITH GUSTS TO 90 KT. PLEASE READ THE FORECAST/ADVISORY UNDER 
AFOS/ WMO HEADERS TCMAT3/WTNT23 KNHC AND THE PUBLIC ADVISORY 
UNDER TCPAT3/WTNT33 KNHC FOR MORE DETAILS. NUMEROUS STRONG 
SHOWERS AND THUNDERSTORMS ARE FROM 39N TO 40N BETWEEN 66W AND 
68W.

...TROPICAL WAVES...
AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20W TO THE 
SOUTH OF 16N MOVING WEST 10 KT. DISORGANIZED ISOLATED MODERATE 
SHOWERS AND THUNDERSTORMS ARE WITHIN 30 NM ON EITHER SIDE OF
15N22W 12N25W 8N27W...AND FROM 10N TO 16N BETWEEN AFRICA AND 
21W. 

AN ATLANTIC OCEAN TROPICAL WAVE HAS BEEN RE-LOCATED FROM 43W/44W 
TO 48W BASED ON THE SATELLITE IMAGERY. THE WAVE IS TO THE SOUTH 
OF 18N MOVING WESTWARD 20 TO 25 KT. DISORGANIZED ISOLATED 
MODERATE SHOWERS AND THUNDERSTORMS FROM 10N TO 21N BETWEEN 40W 
AND 54W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 67W TO THE SOUTH OF 17N 
MOVING WEST 15 TO 20 KT. DISORGANIZED ISOLATED MODERATE SHOWERS
AND THUNDERSTORMS ARE TO THE SOUTH OF 13N BETWEEN 60W AND 70W. 

THE ITCZ...
FROM 11N22W TO 12N37W 10N53W TO 10N61W NEAR TRINIDAD AND
VENEZUELA. ISOLATED MODERATE SHOWERS ARE ELSEWHERE TO THE SOUTH 
OF 20N TO THE EAST OF 50W...AND TO THE SOUTH OF 15N BETWEEN
50W AND 60W.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL TROUGH PASSES THROUGH CENTRAL ALABAMA TO THE 
NORTHWESTERN GULF. THIS TROUGH IS PUSHING THE CURRENT GULF COLD 
FRONT ACROSS THE GULF OF MEXICO TO THE NORTH OF 26N. SHOWERS AND
THUNDERSTORMS REMAIN...AND SOME ARE DISSIPATING WHILE OTHERS 
ALTERNATELY ARE DEVELOPING...TO THE NORTH OF 22N BETWEEN FLORIDA 
AND 95W. AN INVERTED UPPER LEVEL TROUGH CURVES FROM THE 
SOUTHEASTERN CORNER OF THE AREA TO JUST TO THE NORTH OF THE 
YUCATAN PENINSULA...INTO THE SOUTHWESTERN CORNER OF THE AREA. 
SHOWERS ARE POSSIBLE NEAR THIS TROUGH. DISSIPATING PRECIPITATION
IS IN THE ISTHMUS OF TEHUANTEPEC AT THIS MOMENT.
 
THE CARIBBEAN SEA...
BROAD UPPER LEVEL ANTICYCLONIC FLOW MOVES FROM EAST TO WEST...
FROM THE EASTERN CARIBBEAN SEA ISLANDS TO 80W. THE EXTREME 
NORTHWESTERN CORNER OF THE AREA IS COVERED BY CYCLONIC FLOW FROM 
AN UPPER LEVEL INVERTED TROUGH THAT RUNS FROM THE SOUTHEASTERN 
CORNER OF THE GULF OF MEXICO INTO THE SOUTHWESTERN CORNER OF THE 
AREA. OTHER SHOWERS AND POSSIBLE THUNDERSTORMS ARE MOVING ACROSS 
THE AREA FROM 11N TO 16N BETWEEN 80W AND THE COAST OF NICARAGUA
AND EASTERN HONDURAS...WITH A SMALL MIDDLE LEVEL TROUGH.

THE ATLANTIC OCEAN...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH GOES FROM A CYCLONIC 
CIRCULATION CENTER THAT IS NEAR 31N70W INTO THE CENTRAL BAHAMA 
ISLANDS. ISOLATED MODERATE SHOWERS ARE WITHIN 60 NM TO 120 NM
TO THE EAST OF THE TROUGH. A MIDDLE LEVEL TO UPPER LEVEL TROUGH 
EXTENDS FROM A 26N57W CYCLONIC CIRCULATION CENTER TO 19N56W TO 
14N60W. DISORGANIZED ISOLATED MODERATE SHOWERS ARE FROM 14N TO 
32N BETWEEN 50W AND 60W.

$$
MT