000
AXNT20 KNHC 141149
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT WED OCT 14 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1015 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 60W S OF 13N MOVING W NEAR 15 KT. WAVE IS 
EMBEDDED WITHIN THE ITCZ AT LOW AMPLITUDE AND WITHIN AN AREA OF 
DEEP MOISTURE AS INDICATED IN THE TOTAL PRECIPITABLE WATER 
IMAGERY WITH SATELLITE DERIVED WINDS SHOWING A WELL DEFINED 
CYCLONIC CURVATURE. ISOLATED SHOWERS ARE FROM 10N-12N BETWEEN 
58W-62W INCLUDING THE WINDWARD ISLANDS. 

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 11N12W 7N20W 8N28W 7N35W 10N48W 
8N60W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 
27W/28W FROM 5N-10N AND A SECOND SURFACE TROUGH ALSO EMBEDDED 
WITHIN THE ITCZ FROM 13N46W TO 8N47W. CLUSTERS OF SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION ARE FROM 5N-11N BETWEEN 
16W-35W AND FROM 5N-14N BETWEEN 44W-53W. 

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE CONTINUES TO DOMINATE THE GULF ANCHORED NEAR 
26N92W WITH AN AXIS EXTENDING E INTO THE W ATLC ACROSS FLORIDA 
NEAR LAKE OKEECHOBEE. MOSTLY DRY STABLE AIR DOMINATES THE AREA 
WITH DENSE LOW LEVEL CLOUDS AND LINGERING ISOLATED SHOWERS OVER 
THE NE GULF N OF 28N E OF 90W. THE REMAINDER OF THE GULF IS 
EXPERIENCING FAIR WEATHER WITH CLEAR SKIES AGAIN THIS MORNING. A 
SURFACE RIDGE CONTINUES TO SLOWLY BUILD WESTWARD ACROSS THE NE 
GULF.  

CARIBBEAN SEA...
THE BROAD UPPER RIDGE THAT COVERS MOST OF THE ATLC AND GULF OF 
MEXICO IS GIVING MOST OF THE CARIBBEAN UPPER EASTERLY WINDS N OF 
A SHEAR AXIS THAT ENTERS THE CARIBBEAN OVER THE LESSER ANTILLES 
BETWEEN MARTINIQUE AND DOMINICA ALONG 13N71W TO E PANAMA NEAR 
9N77W PRODUCING PATCHES OF SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS NW OF A LINE FROM THE LESSER ANTILLES NEAR 
GUADELOUPE ALONG 16N77W TO HONDURAS NEAR 16N84W AND IN THE SW 
CARIBBEAN S OF A LINE FROM COLOMBIA NEAR 10N76W TO NICARAGUA 
NEAR 12N84W. THE REMAINDER OF THE CARIBBEAN IS UNDER A VERY DRY 
AND STABLE AIRMASS GIVING THAT AREA CLEAR SKIES AGAIN THIS 
MORNING. 

ATLANTIC OCEAN...
A COLD FRONT ENTERS THE REGION OVER BERMUDA EXTENDING W TO 
29N74W THEN DISSIPATING TO 28N78W. THE UPPER LEVEL TROUGH 
SUPPORTING THIS FRONT REMAINS JUST N OF THE REGION. THE BROAD 
UPPER RIDGE THAT DOMINATES THE ATLC W OF 40W EXTENDS AN AXIS 
ACROSS THE GULF AND THE FLORIDA PENINSULA N OF LAKE OKEECHOBEE 
TO NEAR 25N40W AND IS PROVIDING DIFFLUENCE ALOFT TO GENERATE 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 29N BETWEEN 
46W-64W. A SHARP UPPER TROUGH DIGS S INTO THE E ATLC NEAR 32N32W 
S TO 14N33W THEN EXTENDS W AS A SHEAR AXIS ALONG 18N48W OVER THE 
LESSER ANTILLES BETWEEN MARTINIQUE AND DOMINICA INTO THE S 
CARIBBEAN. THIS UPPER TROUGH CONTINUES TO SUPPORT A WEAKENING 
1012 MB SURFACE LOW CENTERED NEAR 28N35W WITH A SURFACE TROUGH 
EXTENDING ALONG 30N32W 28N31W THEN SW TO 24N42W. SCATTERED 
SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 24N-30N  
BETWEEN 23W AND THE ABOVE SURFACE TROUGH.  
 
$$
WALLACE