000
AXNT20 KNHC 182334
TWDAT 

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

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 8N13W 7N20W 9N28W 6N35W 11N60W. 
WIDELY SCATTERED MODERATE CONVECTION IS FROM 6N-10N BETWEEN 
18W-25W. SCATTERED MODERATE CONVECTION IS FROM 14N-16N BETWEEN 
55W-58W.  

...DISCUSSION...

GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT EXTENDS FROM THE FLORIDA PANHANDLE 
NEAR 30N83W TO THE SE GULF OF MEXICO NEAR 24N86W. A STATIONARY 
FRONT CONTINUES TO THE THE BAY OF CAMPECHE TO 20N94W 18N95W. 
SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONTS. A STATIONARY 
FRONT IS INLAND OVER MEXICO E OF THE SIERRA MADRE ORIENTAL 
MOUNTAINS ALONG 17N96W 20N98W 24N99W. SCATTERED SHOWERS ARE 
WITHIN 180 NM E OF THE FRONT TO THE GULF COAST. A 1020 MB HIGH 
IS CENTERED ALONG THE COAST OF LOUISIANA NEAR 29N93W. 10-15 KT 
ANTICYCLONIC WINDS ARE NOTED OVER THE GULF. MOSTLY FAIR WEATHER 
IS OVER THE NW GULF N OF 26N AND W OF 88W. IN THE UPPER 
LEVELS...A BROAD TROUGH IS OVER THE GULF PRODUCING MOSTLY ZONAL 
FLOW AND STRONG SUBSIDENCE. EXPECT OVER THE NEXT 24 HOURS FOR 
THE NORTHERN PORTION OF THE FRONT TO DRIFT TO CENTRAL FLORIDA 
WHILE THE SOUTHERN PORTION OF THE FRONT TO RETROGRADE BACK NORTH 
TOWARDS THE S TEXAS COAST WITH SHOWERS.  

CARIBBEAN SEA...
MODERATE TO FRESH TRADEWINDS DOMINATES THE BASIN. PATCHES OF 
BROKEN TO OVERCAST LOW CLOUDS DOTS THE CARIBBEAN AND CENTRAL 
AMERICA NAMELY OVER PUERTO RICO...HISPANIOLA...E CUBA BETWEEN 
76W-80W...NEAR THE CAYMAN ISLANDS FROM 18N-21N BETWEEN 81W-84W 
...THE SW CARIBBEAN W OF 80W...AND INLAND FROM S GUATEMALA S TO 
PANAMA. THE ITCZ ALSO TRAVERSES NORTHERN SOUTH AMERICA FROM 
TRINIDAD TO N COLOMBIA TO PANAMA WITH BROKEN TO OVERCAST 
MULTILAYERED CLOUDS AND ISOLATED MODERATE CONVECTION. A SURFACE 
TROUGH IS OVER THE WINDWARD ISLANDS PRODUCING SHOWERS S OF 17N 
AND E OF 62W. IN THE UPPER LEVELS...THE CARIBBEAN IS 
EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF DRY 
AIR AND SUBSIDENCE N OF 12N. SIGNIFICANT UPPER LEVEL MOISTURE IS 
S OF 12N DUE TO THE ITCZ. EXPECT... SHOWERS/THUNDERSTORMS TO 
CONTINUE OVER THE SW CARIBBEAN OVER THE NEXT 24 HOURS. ALSO 
EXPECT...SIMILAR CONVECTION OVER THE WINDWARD ISLANDS AS THE 
SURFACE TROUGH DRIFTS W OVER THE NEXT 24 HOURS.  

ATLANTIC OCEAN...
A 1012 MB LOW IS OVER THE W ATLANTIC NEAR 26N66W. A SURFACE 
TROUGH EXTENDS S FROM THE LOW TO N OF HISPANIOLA NEAR 20N70W. A 
SECOND SURFACE TROUGH IS FURTHER E ALONG 29N55W 21N60W. WIDELY 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM OF THIS TROUGH. 
THIS CONVECTIVE ACTIVITY IS ALSO ENHANCED BY DIFFLUENT FLOW 
ALOFT FROM AN UPPER LEVEL LOW CENTERED NEAR 26N61W. THE TAIL END 
OF A COLD FRONT IS OVER THE CENTRAL ATLANTIC FROM 32N50W TO 
31N60W 31N65W. A 1023 MB HIGH IS CENTERED OVER THE E ATLANTIC 
NEAR 35N15W. A RIDGE AXIS EXTENDS SW FROM THE HIGH TO 29N30W 
24N50W. 
 
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FORMOSA