000
AXNT20 KNHC 302350
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST WED NOV 30 2011 

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...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS SW AFRICA AND REACHES GUINEA 
NEAR 11N15W. THE ITCZ CONTINUES TO 8N20W TO 7N40W TO 8N60W. 
WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-9N BETWEEN 
20W-34W...AND FROM 8N-12N BETWEEN 57W-59W.

...DISCUSSION...

THE GULF OF MEXICO...
AS OF 2100 UTC...A 1023 MB HIGH IS CENTERED OVER MISSISSIPPI 
NEAR 33N90W. 10-15 KT N FLOW IS OVER THE GULF OF MEXICO. 
SCATTERED COLD AIR STRATOCUMULUS CLOUDS ARE OVER THE E GULF E OF 
86W. MORE LOW CLOUDS ARE ALONG THE COAST OF THE YUCATAN 
PENINSULA. FAIR WEATHER IS OVER THE REMAINDER OF THE GULF. SOME 
COLD AIR ADVECTION REMAINS OVER THE N GULF N OF 25N. IN THE 
UPPER LEVELS ZONAL FLOW IS NOTED WITH STRONG SUBSIDENCE. EXPECT 
OVER THE NEXT 24 HOURS FOR SURFACE WINDS IN THE GULF TO BECOME 
MORE ANTICYCLONIC AROUND THE SURFACE HIGH AND THUS TERMINATE THE 
COLD AIR ADVECTION.  

THE CARIBBEAN SEA...
AS OF 2100 UTC...A STATIONARY FRONT EXTENDS FROM E CUBA AT 
21N76W TO COSTA RICA AT 10N83W. PATCHES OF BROKEN LOW CLOUDS ARE 
N OF THE FRONT OVER THE NW CARIBBEAN AND CENTRAL AMERICA. THE 
MONSOON TROUGH EXTENDS FROM N COLOMBIA TO COSTA RICA. SCATTERED 
SHOWERS ARE FROM 7N-10N BETWEEN 75W-85W. FURTHER N...SCATTERED 
SHOWERS ARE OVER THE HIGHER ELEVATIONS OF E CUBA AND HISPANIOLA. 
ELSEWHERE...A SURFACE TROUGH EXTENDS FROM NE VENEZUELA TO THE 
WINDWARD ISLANDS ALONG 11N64W 16N60W. SCATTERED SHOWERS ARE E OF 
THE TROUGH AXIS. IN THE UPPER LEVELS...A LARGE UPPER LEVEL HIGH 
IS CENTERED OVER NICARAGUA. AN UPPER LEVEL TROUGH IS OVER THE E 
CARIBBEAN E OF 70W. STRONG SUBSIDENCE COVERS MOST OF THE 
CARIBBEAN EXCEPT OVER THE WINDWARD ISLANDS. EXPECT...FOR THE 
FRONT TO DISSIPATE OVER THE NEXT 24 HOURS. ALSO EXPECT FOR THE 
SHOWERS OVER THE SW CARIBBEAN...AND SE CARIBBEAN...TO PERSIST.

THE ATLANTIC OCEAN...
AS OF 2100 UTC...A COLD FRONT IS OVER THE W ATLANTIC FROM 30N70W 
TO E CUBA AT 21N76W. SCATTERED SHOWERS ARE WITHIN 30 NM W OF THE 
FRONT. A 1005 MB LOW IS NE OF THE LEEWARD ISLANDS NEAR 25N60W. A 
SURFACE TROUGH EXTENDS S FROM THE LOW TO THE WINDWARD ISLANDS AT 
16N60W. SCATTERED SHOWERS ARE WITHIN 240 NM E OF THE TROUGH 
AXIS. GALE-FORCE WINDS ARE WITHIN 300 NM IN THE NORTHEASTERN 
SEMICIRCLE. SEA HEIGHTS RANGE FROM FROM 10 TO 16 FEET IN 
PRIMARILY SOUTHEASTERN SWELL. ADDITIONAL INFORMATION ON THIS 
SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE 
NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO 
HEADER FZNT01 KWBC. A 1032 MB HIGH IS OVER THE CENTRAL ATLANTIC 
NEAR 42N44W. IN THE UPPER LEVELS...AN UPPER TROUGH IS BETWEEN 
60W-70W. UPPER LEVEL DIFFLUENCE E OF THE TROUGH IS PRODUCING 
SCATTERED SHOWERS N OF 15N BETWEEN 50W-60W. EXPECT...FOR THE 
COLD FRONT TO MOVE E OVER THE NEXT 24 HOURS WITH SHOWERS. ALSO 
EXPECT CONTINUED CONVECTION NE OF THE LEEWARD ISLANDS DUE TO THE 
SURFACE LOW AND UPPER LEVEL DIFFLUENCE.   

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

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FORMOSA