000
AXNT20 KNHC 242348
TWDAT 

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

...TROPICAL WAVES...

A TROPICAL WAVE IS W OF THE CAPE VERDE ISLANDS ALONG 27W SOUTH 
OF 18N MOVING WEST ABOUT 15 KT. A 1010 MB LOW IS CENTERED ON THE 
WAVE AXIS NEAR 14N27W. THIS SYSTEM SHOWS UP WELL ON SATELLITE 
IMAGERY AND ON THE SSMI TOTAL PRECIPITABLE WATER IMAGERY. A BAND 
OF DRY AIR AND DUST HAS WRAPPED AROUND THE NORTH...WEST...AND 
SOUTH SIDES OF THE TROPICAL WAVE AND LOW. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS W OF THE WAVE AXIS FROM 13N-18N 
BETWEEN 26W-31W. 

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 56W SOUTH OF 20N MOVING 
W AT 20 KT. AN INVERTED-V LOW CLOUD PATTERN IS NOTED ON 
SATELLITE IMAGERY. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS ON THE WAVE AXIS FROM 08N-13N BETWEEN 55W-58W. 

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 12N16W 14N24W 9N40W 11N56W 
10N62W. BESIDES THE CONVECTION MENTIONED ON THE TROPICAL WAVE 
SECTION...SCATTERED MODERATE TO STRONG CONVECTION IS ALONG THE 
COAST OF WEST AFRICA FROM 10N-13N BETWEEN 14W-17W. WIDELY 
SCATTERED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 24W-28W.

...DISCUSSION...

THE GULF OF MEXICO...

A STATIONARY FRONT EXTENDS FROM SOUTHERN LOUISIANA NEAR 30N92W 
TO THE SW GULF OF MEXICO ALONG 24N96W 18N94W. WIDELY SCATTERED 
MODERATE CONVECTION IS W OF THE FRONT TO THE MAINLAND AT 98W.  
WIDELY SCATTERED MODERATE CONVECTION IS ALSO INLAND OVER S FROM 
17N-20N BETWEEN 90W-94W. SIMILAR CONVECTION IS OFF THE SW 
FLORIDA COAST NEAR NAPLES. MOSTLY FAIR WEATHER IS OVER THE 
REMAINDER OF THE GULF. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH 
IS OVER THE CENTRAL GULF NEAR 30N90W. CONSIDERABLE UPPER LEVEL 
MOISTURE IS OVER TEXAS AND THE W GULF...AND OVER THE YUCATAN 
PENINSULA. STRONG SUBSIDENCE IS OVER THE CENTRAL AND EASTERN 
GULF. EXPECT...THE STATIONARY FRONT TO REMAIN STATIONARY OVER 
THE NEXT 24 HOURS WITH CONVECTION.   

THE CARIBBEAN SEA...

FRESH TO STRONG TRADEWINDS ARE OVER THE CARIBBEAN SEA AND 
CENTRAL AMERICA. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS OVER THE W CARIBBEAN W OF 80W. SCATTERED MODERATE  
CONVECTION IS OVER THE HIGHER ELEVATIONS OF PUERTO 
RICO...HISPANIOLA...AND CUBA. PATCHES OF SCATTERED 
MODERATE CONVECTION IS ALSO INLAND OVER CENTRAL AMERICA FROM 
PANAMA TO GUATEMALA. IN THE UPPER LEVELS... A RIDGE IS OVER THE 
W CARIBBEAN W OF 80W. THE BASE OF AN UPPER LEVEL TROUGH IS OVER 
THE REMAINDER OF THE CARIBBEAN E OF 80W. EXPECT...CONTINUED 
CONVECTION OVER THE N CARIBBEAN N OF 18N... AND OVER THE W 
CARIBBEAN W OF 80W OVER THE NEXT 24 HOURS. ALSO EXPECT 
CONVECTION OVER THE WINDWARD ISLANDS FROM AN APPROACHING 
TROPICAL WAVE.  

THE ATLANTIC OCEAN...

A SURFACE TROUGH IS OVER THE W ATLANTIC ALONG 32N63W 24N65W 
WIDELY SCATTERED MODERATE CONVECTION IS FROM 30N-32N BETWEEN 
55W-63W. ANOTHER SURFACE TROUGH IS FURTHER E ALONG 27N52W 
21N55W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 
23N-28N BETWEEN 50W-53W. IN THE UPPER LEVELS...AN UPPER LEVEL 
LOW IS OVER THE W ATLANTIC NEAR 27N64W. ZONAL FLOW IS N OF 20N 
AND E OF 50W TO W AFRICA. TWO UPPER LEVEL HIGHS ARE OVER THE 
TROPICAL ATLANTIC NEAR 12N45W AND 17N28W. EXPECT THE TROPICAL 
WAVES TO BE THE DOMINATE FEATURES OVER THE NEXT 24 HOURS. 

$$
FORMOSA