000
AXNT20 KNHC 131750
TWDAT 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST THU NOV 13 2008

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.

...THE ITCZ...
THE AXIS IS ANALYZED ALONG 9N13W 6N20W 8N42W 6N57W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-7N BETWEEN 
11W-17W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE FROM 
6N-11N BETWEEN 42W-49W.

...DISCUSSION...

GULF OF MEXICO...
A DEEP LAYERED TROUGH EXTENDS FROM THE CENTRAL PLAINS TO OVER 
MEXICO DRAWING TROPICAL MOISTURE ACROSS SRN MEXICO AND THE NW 
GULF WITH A COLD FRONT EXTENDING FROM A 1014 MB LOW CENTERED 
OVER S/CENTRAL ALABAMA NEAR 31N87W. THIS FRONT ENTERS THE GULF 
NEAR MOBILE ALABAMA AND EXTENDS SW TO 26N95W THEN INLAND OVER 
MEXICO NEAR LA LUZ. A PRE-FRONTAL TROUGH EXTENDS FROM THE COLD 
FRONT NEAR 25N96W TO 22N98W. BANDS OF SCATTERED/NUMEROUS SHOWERS 
WITH EMBEDDED SCATTERED TSTMS ARE ACROSS THE GULF WATERS NW OF 
THESE FRONTAL BOUNDARIES. A WEAK SURFACE TROUGH IS ACROSS THE SE 
GULF AND EXTENDS FROM 26N85W TO THE WRN TIP OF CUBA. SCATTERED 
SHOWERS ARE ACROSS THE ERN GULF E OF 88W WITH THIS WEAK CYCLONIC 
LOW-LEVEL TURNING AS MOIST AND UNSTABLE AIR IS IN PLACE E OF THE 
COLD FRONT. THE REMAINDER OF THE GULF IS UNDER A BROAD UPPER 
RIDGE THAT IS ANCHORED IN THE CARIBBEAN AND EXTENDS ACROSS THE 
FLORIDA PENINSULA.

CARIBBEAN SEA...
A BROAD UPPER RIDGE DOMINATES THE WRN CARIBBEAN AND IS ANCHORED 
NEAR 17N81W. IT COVERS THE BASIN W OF 73W AND EXTENDS A RIDGE 
AXIS N ACROSS CUBA COVERING PORTIONS OF THE GULF OF MEXICO AND 
THE W ATLC. UPPER DIFFLUENCE COUPLED WITH LOW LEVEL CONVERGENCE 
IS SUPPORTING SCATTERED SHOWERS AND TSTMS S OF 12N IN THE SW 
CARIBBEAN. AN UPPER LOW OVER THE VIRGIN ISLANDS COVERS THE 
REMAINDER OF THE CARIBBEAN E OF 73W AND INTO THE W/CENTRAL ATLC. 
THIS FEATURE ALONG WITH A SURFACE TROUGH EXTENDING ACROSS THE 
LEEWARD ISLANDS ARE GENERATING SCATTERED SHOWERS/ISOLATED TSTMS 
OVER THE CARIBBEAN E OF 65W. THE REMAINDER OF THE CARIBBEAN IS 
DOMINATED BY MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR BUT 
ISOLATED SHALLOW TOPPED SHOWERS ARE ACROSS MOST OF THE BASIN. 

ATLANTIC OCEAN...
THE UPPER RIDGE ANCHORED IN THE WRN CARIBBEAN EXTENDS AN AXIS N 
OVER THE FLORIDA PENINSULA AND W ATLC BEYOND 32N75W. SOUTHERLY 
RETURN FLOW RESIDES ACROSS THE W ATLC W OF 73W AS A PAIR OF WEAK 
SURFACE LOWS ARE ACROSS THE SE CONUS WITH A STATIONARY FRONT 
BRIDGING THEM ACROSS SRN GEORGIA. A SURFACE RIDGE COVERS THE 
REMAINDER OF THE W ATLC N OF 20N AND W OF 67W. AN UPPER LOW 
CENTERED OVER THE VIRGIN ISLANDS COVERS THE REMAINDER OF THE W 
ATLC AND EXTENDS INTO THE CENTRAL ATLC. IT COVERS THE AREA S OF 
25N BETWEEN 55W-73W WITH A SURFACE TROUGH EXTENDING FROM 26N59W 
ACROSS THE LEEWARD ISLANDS TO 17N63W. SCATTERED SHOWERS/TSTMS 
ARE FROM 15N-25N BETWEEN 56W-64W...INCLUDING THE LESSER 
ANTILLES. NEARLY ZONAL UPPER FLOW IS OVER THE E ATLC N OF 23N  
AND E OF 53W WITH A WEAK SURFACE TROUGH EXTENDING FROM 31N37W TO 
24N35W. SCATTERED SHOWERS ARE E OF THE SURFACE TROUGH FROM 
24N-27N BETWEEN 32W-36W. A SURFACE RIDGE COVERS THE NE ATLC N OF 
23N E OF 30W ANCHORED NE OF THE AZORES.

$$
HUFFMAN