000
AXNT20 KNHC 202355
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST FRI NOV 20 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 10N12W 6N25W 7N44W 7N60W. WIDELY 
SCATTERED MODERATE CONVECTION IS FROM 3N-7N BETWEEN 24W-32W. 
SIMILAR CONVECTION IS FOCUSED ALONG A SURFACE TROUGH EMBEDDED 
WITHIN THE ITCZ FROM 12N42W TO 5N45W. THE CONVECTION COVERS AN 
AREA FROM 7N-10N BETWEEN 39W-48W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 2100 UTC...A 1010 MB LOW IS CENTERED OFF THE COAST OF 
TEXAS NEAR 27N95W. A WARM FRONT EXTENDS E FROM THE LOW TO 
26N90W. A SURFACE TROUGH ALSO EXTENDS S FROM THE LOW CENTER TO 
24N98W. 25 KT WINDS ARE NOTED OVER THE NW GULF OF MEXICO IN 
VICINITY OF THE LOW. WIDELY SCATTERED MODERATE CONVECTION IS 
FROM 25N-30N BETWEEN 90W-94W. IN THE UPPER LEVELS...ZONAL FLOW 
COVERS THE GULF. SIGNIFICANT UPPER LEVEL MOISTURE IS OVER THE N 
GULF N OF 26N. STRONG SUBSIDENCE COVERS THE S GULF. EXPECT THE 
SURFACE LOW TO MOVE TO THE MISSISSIPPI COAST IN 24 HOURS WITH A 
TRAILING COLD FRONT EXTENDING S TO THE YUCATAN PENINSULA AND A 
WARM FRONT OVER THE FLORIDA PANHANDLE. EXPECT 15-20 KT N WINDS W 
OF THE COLD FRONT AND 10 KT S WINDS E OF THE COLD FRONT. ALSO 
EXPECT CONVECTION TO BE ALONG THE WARM FRONT OVER N FLORIDA AND 
E OF THE COLD FRONT OVER THE S GULF OF MEXICO.  

CARIBBEAN SEA...
MODERATE TO FRESH TRADEWINDS DOMINATES THE BASIN. A 1004 MB LOW 
IS CENTERED INLAND OVER N COLOMBIA NEAR 8N75W. WIDELY SCATTERED 
MODERATE CONVECTION IS FROM 4N-9N BETWEEN 75W-79W. PATCHES OF 
BROKEN TO OVERCAST LOW CLOUDS DOTS THE CARIBBEAN AND CENTRAL 
AMERICA NAMELY OVER THE WINDWARD ISLANDS S OF 14N AND E OF 
62W...OVER PUERTO RICO...HISPANIOLA...AND THE NW CARIBBEAN FROM 
17N-22N BETWEEN 82W-90W. SIMILAR SHOWERS ARE OVER THE SW 
CARIBBEAN S OF 11N. IN THE UPPER LEVELS...A BROAD RIDGE IS 
PRODUCING ZONAL FLOW OVER THE ENTIRE CARIBBEAN. DRY AIR AND 
SUBSIDENCE COVERS THE ENTIRE AREA WITH UPPER LEVEL MOISTURE 
REMAINING ONLY OVER N COLOMBIA. EXPECT...SHOWERS/THUNDERSTORMS 
TO CONTINUE OVER THE SW CARIBBEAN OVER THE NEXT 24 HOURS. ALSO 
EXPECT...SIMILAR CONVECTION OVER THE WINDWARD ISLANDS. 

ATLANTIC OCEAN...
A 1012 MB LOW IS OVER THE W ATLANTIC NEAR 32N75W. A SURFACE 
TROUGH EXTENDS S FROM THE LOW TO THE CENTRAL BAHAMAS NEAR 
25N75W. SCATTERED SHOWERS ARE WITHIN 180 NM OF THE TROUGH AXIS.
ANOTHER SURFACE TROUGH IS OVER THE W ATLANTIC N OF PUERTO RICO 
ALONG 25N64W 19N66W. SCATTERED SHOWERS ARE WITHIN 240 NM E OF 
THIS TROUGH AXIS. A LONG STATIONARY FRONT IS OVER THE ATLANTIC 
ALONG 32N26W 29N33W TO AN EMBEDDED 1015 MB LOW NEAR 27N51W TO 
30N64W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 25N-28N 
BETWEEN 46W-52W...AND FROM 28N-31N BETWEEN 59W-68W. FURTHER E 
...A RIDGE AXIS EXTENDS FROM S PORTUGAL TO SW OF THE CANARY 
ISLANDS NEAR 25N27W. EXPECT THE LOW OVER THE W ATLANTIC TO MOVE 
NE OVER THE NEXT 24 HOURS LEAVING THE TAIL END OF A SURFACE 
TROUGH OVER THE AREA S OF 30N. ALSO EXPECT MORE CONVECTION OVER 
THE CENTRAL ATLANTIC FROM 20N-32N BETWEEN 40W-55W DUE TO THE 
CENTRAL ATLANTIC LOW OVER THE NEXT 24 HOURS.  

$$
FORMOSA