000
AXNT20 KNHC 120542
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST THU NOV 12 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 10N14W 6N35W 5N53W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-16N BETWEEN 
18W-30W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-9N 
BETWEEN 32W-44W.
 
...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL WESTERLY FLOW DOMINATES ACROSS THE GULF OF MEXICO 
BEHIND AN UPPER LEVEL SHORTWAVE TROUGH CURRENTLY LOCATED OVER 
THE SE CONUS AND MID-ATLANTIC STATES MOVING OFF TO THE NE. WITH 
THE RECENT COLD FRONTAL PASSAGE WITHIN THE LAST 24 HOURS... 
STRONG NORTHERLY WINDS UP TO 25 KT ARE OBSERVED ACROSS THE GULF. 
STRONG SUBSIDENCE IS NOTED ON WATER VAPOR IMAGERY OVER THE GULF 
PROVIDING A COOLER AND STABLE AIRMASS OVER THE REGION. THE 
NORTHERLY WINDS ARE FORECAST TO GRADUALLY DIMINISH THROUGH 
FRIDAY...WITH S-SE RETURN FLOW RETURNING OVER WESTERN PORTIONS 
OF THE GULF BY EARLY SATURDAY AHEAD OF AN AREA OF DEVELOPING LOW 
PRESSURE OVER THE SOUTHERN U.S. PLAINS AND THE ASSOCIATED COLD 
FRONT EXPECTED TO ENTER THE NW GULF WATERS BY MONDAY. 

CARIBBEAN SEA...
A COLD FRONT EXTENDS FROM THE W ATLC AND STRAITS OF FLORIDA 
ACROSS WESTERN CUBA AND INTO THE NW CARIBBEAN ALONG 22N82W TO 
N/CENTRAL HONDURAS NEAR 15N86W. A 1007 MB LOW IS ALSO ANALYZED E 
OF THE FRONT NEAR 16N82W. SCATTERED SHOWERS AND ISOLATED TSTMS 
ARE OCCURRING WITHIN 90 NM E OF THE FRONT N OF 20N AND FROM 
14N-20N BETWEEN 81W-86W. THIS FRONT IS SUPPORTED BY AN UPPER 
LEVEL SHORTWAVE TROUGH LOCATED OVER THE MID-ATLANTIC STATES AND 
FAR W ATLC WATERS. SOUTH OF THIS UPPER LEVEL TROUGHING...AN 
UPPER LEVEL RIDGE IS ANCHORED IN THE SW CARIBBEAN NEAR 11N79W 
AND COVERS MUCH OF THE WESTERN CARIBBEAN W OF 70W. UPPER LEVEL 
DIFFLUENCE OVER PORTIONS OF CENTRAL AMERICA IS GENERATING 
SCATTERED SHOWERS OVER PANAMA...COSTA RICA...AND ADJACENT 
COASTAL WATERS S OF 10N. THE REMAINDER OF THE CARIBBEAN IS UNDER 
THE INFLUENCE OF UPPER LEVEL TROUGHING E OF 70W. WITH THE UPPER 
TROUGH AXIS ALONG 62W...SCATTERED SHOWERS ARE OCCURRING OVER THE 
NE CARIBBEAN N OF 15N E OF 68W...ALSO INCLUDING THE LESSER 
ANTILLES BETWEEN 60W-63W. 

ATLANTIC OCEAN...
AN UPPER LEVEL SHORTWAVE TROUGH IS ACROSS THE MID-ATLANTIC 
STATES AND EXTENDS INTO THE FAR W ATLC WATERS W OF 77W. THIS 
TROUGH SUPPORTS A 1003 MB LOW CENTERED NORTH OF THE AREA NEAR 
33N78W WITH A COLD FRONT EXTENDING SOUTHWARD ALONG 30N78W 25N80W 
AND ACROSS WESTERN CUBA INTO THE NW CARIBBEAN SEA. SCATTERED 
SHOWERS AND ISOLATED TSTMS ARE WITHIN 120 NM E OF THE FRONT. 
FARTHER E...A 1004 MB LOW IS CENTERED NEAR 27N66W AND IS 
SUPPORTED BY AN UPPER LEVEL SHORTWAVE TROUGH WITH AXIS EXTENDING 
FROM 30N65W TO 17N60W. UPPER LEVEL DIFFLUENCE E OF THE TROUGH 
AXIS IS GENERATING SCATTERED SHOWERS AND TSTMS COVERING THE AREA 
FROM 20N-29N BETWEEN 60W-65W. ANOTHER AREA OF SCATTERED SHOWERS 
AND ISOLATED TSTMS INFLUENCED BY THE UPPER LEVEL LIFT IS AN AREA 
FROM 24N-30N BETWEEN 54W-59W. ELSEWHERE ACROSS THE REMAINDER OF 
THE CENTRAL AND EASTERN ATLC A SURFACE RIDGE DOMINATES ANCHORED 
ON A 1021 MB HIGH CENTERED NEAR 33N37W. AN UPPER LEVEL RIDGE 
WITH AXIS ALONG 50W SUPPORTS THE SURFACE RIDGE.

$$
HUFFMAN