000
AXNT20 KNHC 202340
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU DEC 20 2012

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 EXITS LIBERIA NEAR 5N9W...THEN EXTENDS 
WESTWARD TO 5N13W. THE ITCZ CONTINUES TO 5N30W TO 4N40W TO N 
BRAZIL NEAR 3N51W. WIDELY SCATTERED MODERATE CONVECTION IS S OF 
LIBERIA FROM 2N-3N BETWEEN 6W-14W.   

...DISCUSSION...

THE GULF OF MEXICO...
A COLD FRONT EXTENDS FROM THE FLORIDA PANHANDLE NEAR 30N86W TO 
THE BAY OF CAMPECHE 20N95W. SCATTERED MODERATE CONVECTION IS 
OVER N FLORIDA AND THE NE GULF OF MEXICO FROM 28N-31N BETWEEN 
81W-85W. GALE FORCE WINDS ARE OVER THE W GULF W OF FRONT S OF 
27N. 20-30 KT WINDS ARE OVER THE REMAINDER OF THE W GULF W OF 
FRONT. SIGNIFICANT COLD AIR ADVECTION IS ALSO W OF FRONT. IN THE 
UPPER LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE 
GULF WITH BROKEN UPPER LEVEL CLOUDS. EXPECT... THE COLD FRONT TO 
EXTEND IN 24 HOURS FROM THE STRAITS OF FLORIDA TO THE YUCATAN 
PENINSULA WITH CONVECTION. 

THE CARIBBEAN SEA...
15-30 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST 
WINDS ALONG THE COAST OF N COLOMBIA. ISOLATED MODERATE 
CONVECTION IS OVER OVER THE SW CARIBBEAN...N COLOMBIA... 
PANAMA... AND COSTA RICA FROM 7N-10N BETWEEN 74W-80W...AND FROM 
8N-14N BETWEEN 80W-84W. ELSEWHERE...SCATTERED SHOWERS ARE OVER 
THE WINDWARD ISLANDS FROM 10N-13N E OF 63W. MORE SHOWERS ARE 
OVER THE HIGHER ELEVATIONS OF PUERTO RICO...HISPANIOLA...AND 
JAMAICA. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE 
W CARIBBEAN W OF 75W. ZONAL FLOW IS OVER THE REMAINDER OF THE 
CARIBBEAN. EXPECT IN 24 HOURS... FOR CONVECTION TO BE OVER W 
CUBA...THE YUCATAN CHANNEL...AND THE YUCATAN PENINSULA DUE TO 
THE COLD FRONT. ALSO EXPECT CONTINUED PRECIPITATION OVER THE 
SOUTHERN CARIBBEAN. 

THE ATLANTIC OCEAN...
WIDELY SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF N 
FLORIDA N OF 28N W OF 79W DUE TO THE COLD FRONT. A 1021 MB HIGH 
IS CENTERED OVER THE W ATLANTIC NEAR 33N73W. FURTHER E...A COLD 
FRONT EXTENDS FROM 32N43W TO 26N50W TO 20N60W TO N OF HISPANIOLA 
AT 20N70W. SCATTERED SHOWERS ARE WITHIN 45 NM OF THE FRONT. GALE 
FORCE WINDS ARE ON BOTH SIDES OF THE FRONT N OF 29N. A 1024 MB 
HIGH IS CENTERED OVER MOROCCO NEAR 34N6W. A RIDGE AXIS EXTENDS 
SW FROM THE HIGH TO 30N20W TO 24N40W. IN THE TROPICAL ATLANTIC 
...ISOLATED MODERATE CONVECTION IS WITHIN 180 NM OF THE COASTS 
OF NE VENEZUELA...GUYANA AND SURINAME. IN THE UPPER LEVELS...A 
LARGE UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLANTIC N OF 24N 
BETWEEN 35W-65W SUPPORTING THE CENTRAL ATLANTIC COLD FRONT. A 
SMALL UPPER LEVEL LOW IS CENTERED NEAR 20N30W. UPPER LEVEL 
DIFFLUENCE E OF THE LOW IS PRODUCING SCATTERED SHOWERS S OF THE 
CANARY ISLANDS FROM 21N-26N BETWEEN 16W-29W. EXPECT OVER THE 
NEXT 24 HOURS FOR BOTH COLD FRONTS TO MOVE E WITH CONVECTION... 
AND GALE FORCE WINDS N OF N OF 29N.      

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

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FORMOSA