000
AXNT20 KNHC 181743
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE AUG 18 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...SPECIAL FEATURES...
THE EYE OF HURRICANE BILL AT 18/1500 UTC WAS NEAR 15.9N 51.2W...
OR ABOUT 705 MILES/1140 KM TO THE EAST OF THE LEEWARD ISLANDS. 
BILL IS MOVING TOWARD THE WEST-NORTHWEST 14 KT. THE ESTIMATED
MINIMUM CENTRAL PRESSURE IS 963 MB. THE MAXIMUM SUSTAINED WIND 
SPEEDS ARE 90 KT WITH GUSTS TO 110 KT. HURRICANE FORCE WINDS 
EXTEND OUTWARD UP TO 40 MILES/65 KM FROM THE CENTER...AND 
TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES/
280 KM. BILL IS A CATEGORY TWO HURRICANE ON THE SAFFIR-SIMPSON 
SCALE.  STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND 
IT IS POSSIBLE THAT BILL MAY BECOME A MAJOR HURRICANE DURING THE
NEXT DAY OR SO. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT 
IS EXPECTED TO INVESTIGATE BILL THIS AFTERNOON. PLEASE READ
THE LATEST FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
TCMAT3/WTNT23 KNHC FOR MORE DETAILS. STRONG SHOWERS AND 
THUNDERSTORMS ARE FROM 12N TO 13N BETWEEN 39W AND 40W...AND
FROM 10N TO 11N BETWEEN 41W AND 42W. NUMEROUS STRONG SHOWERS
AND THUNDERSTORMS FROM 14N TO 17N BETWEEN 49W AND 53W. SHOWERS
ARE WITHIN 15 NM TO 30 NM ON EITHER SIDE OF 8N54W 9N53W 10N52W.

...TROPICAL WAVES...
AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 35W TO THE 
SOUTH OF 19N MOVING WEST 15 TO 20 KT. DISORGANIZED ISOLATED 
MODERATE SHOWERS COVER THE AREA FROM 13N TO 16N BETWEEN
31W AND 38W.

THE CARIBBEAN SEA TROPICAL WAVE THAT IS ALONG 73W/74W TO THE 
SOUTH OF 20N IS THE REMNANT OF ANA THAT DISSIPATED YESTERDAY.
THIS TROPICAL WAVE IS MOVING WESTWARD 20 KT. STRONG SHOWERS AND 
THUNDERSTORMS HAVE BEEN MOVING WITH THIS WAVE...MOST RECENTLY
FROM 17N TO 21N BETWEEN 73W AND 77W...MOVING ACROSS PARTS OF 
HAITI AND EASTERN CUBA...AND NOW MOVING TOWARD JAMAICA. IT IS 
POSSIBLE THAT SOME PERIODS OF ALTERNATE DEVELOPMENT AND WEAKENING
OF THE PRECIPITATION MAY OCCUR WITHIN THE OVERALL LARGER AREA.

...THE ITCZ...
FROM THE AFRICA COAST FROM 12N TO 13N ALONG 16W...TO 10N28W TO
10N44W 10N53W TO 9N62W IN NORTHEASTERN VENEZUELA. NUMEROUS 
STRONG SHOWERS AND THUNDERSTORMS FROM 12N TO 14N BETWEEN 16W AND 
18W POSSIBLY ACCOMPANY THE NEXT TROPICAL WAVE. DISORGANIZED AND 
ISOLATED MODERATE SHOWERS ARE ELSEWHERE AWAY FROM HURRICANE BILL
FROM 8N TO 12N BETWEEN AFRICA AND 30W...AND FROM 5N TO 10N
BETWEEN 30W AND 60W.

...DISCUSSION...

THE GULF OF MEXICO TO THE EAST OF 86W...THE CARIBBEAN SEA
TO THE NORTH OF 15N TO THE WEST OF 77W...THE ATLANTIC OCEAN
TO THE WEST OF 69W...
A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS 
NEAR 20N80W JUST SOUTH OF CUBA IN THE NORTHWESTERN CARIBBEAN SEA.
CYCLONIC FLOW WITH THIS CENTER COVERS THE AREA FROM 16N/17N IN 
THE CARIBBEAN SEA TO THE NORTHERN BAHAMAS NEAR 25N/26N BETWEEN 
74W AND 86W. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS OCCUR
FROM COASTAL CUBA NEAR 21N TO 24N IN THE BAHAMAS BETWEEN THE 
CENTRAL BAHAMAS NEAR 74W/75W AND 80W. ISOLATED MODERATE SHOWERS 
AND POSSIBLE THUNDERSTORMS ARE IN THE STRAITS OF FLORIDA...IN
THE GULF OF MEXICO TO THE EAST OF 86W...IN THE CARIBBEAN SEA 
FROM 16N TO 20N BETWEEN 80W AND 84W...FROM NAPLES FLORIDA
TO LAKE PLACID FLORIDA TOWARD NORTHEASTERN FLORIDA...AND IN
THE ATLANTIC OCEAN FROM 26N TO 29N BETWEEN 65W AND 77W...
AND FROM 30N TO 32N BETWEEN 62W AND 76W.

THE REST OF THE GULF OF MEXICO...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM LAREDO TEXAS 
THROUGH CENTRAL MEXICO ALONG A NORTH-TO-SOUTH LINE TO A 20N101W
CYCLONIC CIRCULATION CENTER...THAT IS ABOUT 200 NM TO THE NORTH 
OF ACAPULCO. ISOLATED MODERATE SHOWERS COVER THE COASTAL AREAS
FROM 20N TO 25N BETWEEN 96W AND 98W. A MIDDLE LEVEL TO UPPER 
LEVEL TROUGH EXTENDS FROM THE SOUTHWESTERN CORNER OF THE AREA 
ACROSS THE ISTHMUS OF TEHUANTEPEC INTO THE EASTERN PACIFIC 
OCEAN. STRONG SHOWERS AND THUNDERSTORMS FROM 18N TO 22N BETWEEN
94W AND 96W.

THE REST OF THE CARIBBEAN SEA...
MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW IS IN NORTHEASTERN 
COASTAL VENEZUELA FROM 7N TO THE COAST BETWEEN 60W AND 66W.
UPPER LEVEL ANTICYCLONIC FLOW IS TO THE SOUTH OF 11N82W 12N75W 
14N69W TO THE VENEZUELA COAST NEAR 10N65W. ISOLATED MODERATE 
SHOWERS ARE FROM 9N TO 11N BETWEEN 76W AND 83W...ABOUT 200 NM
TO THE NORTH OF THE ITCZ.

THE REST OF THE ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL IS NEAR 32N60W. CYCLONIC FLOW IS WITHIN
120 NM TO 150 NM OF THE CENTER. A CENTRAL ATLANTIC OCEAN MIDDLE
LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N43W TO 28N48W.
ONE MIDDLE LEVEL TO UPPER LEVEL EASTERN ATLANTIC OCEAN TROUGH 
PASSES THROUGH 32N13W TO 27N21W TO 23N23W...TO 22N30W 18N37W AND 
15N40W. A SECOND MIDDLE LEVEL TO UPPER LEVEL TROUGH HAS MOVED 
SOUTHWARD...FROM A 32N22W CYCLONIC CENTER TO 28N23W 26N27W...
AND EVENTUALLY BLENDING WITH THE 32N13W 15N40W TOWARD 22N30W.

$$
MT