000
AXNT20 KNHC 260001
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...SPECIAL FEATURES...

A SURFACE TROUGH THAT HAS BROKEN AWAY FROM A TROPICAL WAVE IS E 
OF THE SOUTHERN BAHAMAS ALONG 24N63W 23N67W 20N68W. SCATTERED 
MODERATE CONVECTION IS IN CLUSTERS FROM 22N-24N BETWEEN 
68W-69W...FROM 22N-26N BETWEEN 60W-66W...AND FROM 20N-22N 
BETWEEN 60W-63W. GALE FORCE WINDS ARE OVER A SMALL AREA WITHIN 
150 NM NE SEMICIRCLE OF 23N67W.  A RECONNAISSANCE AIRCRAFT FOUND 
60 KT WINDS AT A FLIGHT LEVEL OF 900 FT...BUT DID NOT FIND A 
CLOSED LOW LEVEL CENTER. THIS SYSTEM CONTINUES TO SHOW SIGNS OF 
ORGANIZATION...AND UPPER-LEVEL WINDS ARE FORECAST TO BECOME MORE 
CONDUCIVE FOR DEVELOPMENT DURING THE NEXT DAY OR SO AS THE 
SYSTEM MOVES WEST-NORTHWESTWARD AROUND 17 KT. THERE IS A HIGH 
CHANCE OF THIS SYSTEM BECOMING A TROPICAL DEPRESSION OR TROPICAL 
STORM DURING THE NEXT 48 HOURS. 

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 35W S OF 20N MOVING W NEAR 15 KT. A 1010 
MB LOW IS ON THE WAVE AXIS NEAR 15N35W. THE WAVE COINCIDES WITH 
A DEEP LAYER MOISTURE MAXIMUM OBSERVED ON THE SSMI TOTAL 
PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS ARE WITHIN 180 NM 
OF THE WAVE AXIS.

TROPICAL WAVE IS ALONG 69W S OF 19N MOVING W 20-25 KT. WAVE 
COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN THE 
TOTAL PRECIPITABLE WATER IMAGERY.  

TROPICAL WAVE IS ALONG 86W S OF 17N MOVING W 20-25 KT. WAVE 
COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN THE 
TOTAL PRECIPITABLE WATER IMAGERY ACROSS THE SW CARIBBEAN. A 
LOW/MID LEVEL CYCLONIC ROTATION IS OBSERVED OVER CENTRAL AMERICA 
WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 13N-17N 
BETWEEN 80W-87W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 12N15W 11N25W 14N35W 8N40W 7N50W 
9N60W. SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF W 
AFRICA FROM 11N-14N BETWEEN 15W-20W. ISOLATED MODERATE 
CONVECTION IS WITHIN 90 NM OF THE AXIS BETWEEN 40W-60W. 

...DISCUSSION...

GULF OF MEXICO...
A STATIONARY FRONT EXTENDS FROM NE FLORIDA TO THE BAY OF 
CAMPECHE ALONG 30N83W 26N85W 23N90W 20N96W. WIDELY SCATTERED 
MODERATE CONVECTION IS OVER INLAND FLORIDA FROM 26N-29N BETWEEN 
80W-83W. ISOLATED MODERATE CONVECTION IS OVER THE S GULF OF 
MEXICO S OF 24N TO INCLUDE W CUBA...THE YUCATAN PENINSULA...AND 
THE BAY OF CAMPECHE. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS 
CENTERED OVER MISSISSIPPI NEAR 32N90W. A LARGE UPPER LEVEL HIGH 
IS CENTERED OVER THE YUCATAN CHANNEL NEAR 21N86W. SIGNIFICANT 
UPPER LEVEL MOISTURE IS OVER THE S GULF S OF 27N. EXPECT...THE 
STATIONARY FRONT TO DISSIPATE BUT ISOLATED MODERATE CONVECTION 
TO CONTINUE OVER THE S GULF AND FLORIDA FOR THE NEXT 24 HOURS.   
 
CARIBBEAN SEA...
TWO TROPICAL WAVES ARE OVER THE CARIBBEAN. SEE ABOVE. MODERATE 
TO FRESH TRADES ARE OVER THE AREA WITH ISOLATED MODERATE 
CONVECTION OVER HISPANIOLA...AND THE S COAST OF CUBA BETWEEN 
70W-82W. A 1006 MB LOW IS INLAND OVER N COLOMBIA NEAR 9N74W. 
ISOLATED MODERATE CONVECTION IS FROM 8N-11N BETWEEN 71W-77W. IN 
THE UPPER LEVELS...ANTICYCLONIC FLOW IS OVER THE W CARIBBEAN W 
OF 75W. AN UPPER LEVEL LOW IS CENTERED N OF PUERTO RICO NEAR 
21N67W. CYCLONIC FLOW IS OVER THE E CARIBBEAN. EXPECT THE 
SURFACE PRESSURE GRADIENT TO TIGHTEN OVER THE NEXT 24 HOURS AND 
PRODUCE STRONGER TRADEWINDS. ALSO EXPECT MORE SHOWERS AND 
THUNDERSTORMS OVER THE W CARIBBEAN AND CENTRAL AMERICA DUE TO 
THE TROPICAL WAVES.    
 
ATLANTIC OCEAN...
A STATIONARY FRONT ENTERS THE W ATLC NEAR 32N80W EXTENDING 
ACROSS N FLORIDA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE 
WITHIN 180 NM SE OF THE FRONT N OF 28N. A 1024 MB HIGH IS 
CENTERED OVER THE W ATLANTIC NEAR 34N55W. ANOTHER 1023 MB HIGH 
IS CENTERED OVER THE E ATLANTIC NEAR 35N36W. IN THE UPPER 
LEVELS...A LARGE UPPER LEVEL HIGH IS OVER THE CENTRAL ATLANTIC 
NEAR 21N51W. AN UPPER LEVEL LOW IS CENTERED NEAR 25N36W. AN 
UPPER LEVEL HIGH IS OVER THE E ATLANTIC NEAR 19N22W.  

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FORMOSA