000 AXNT20 KNHC 011741 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU DEC 01 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1735 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH REMAINS INLAND ACROSS AFRICA. THE ITCZ EXTENDS ALONG THE COASTS OF GHANA AND COTE D'IVOIRE...ENTERING THE E TROPICAL ATLC ACROSS LIBERIA NEAR 6N10W CONTINUING WESTWARD ALONG 7N20W 8N40W 7N50W ENDING AT 9N55W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 100-150 NM ON EITHER SIDE OF THE ITCZ. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH IS DIGGING S ACROSS THE FAR ERN GULF AND FLORIDA PENINSULA E OF 84W. BEHIND THIS UPPER LEVEL FEATURE...ZONAL WESTERLY FLOW ALOFT PREVAILS ACROSS THE REMAINDER OF THE AREA. THIS DRY STABLE AIRMASS COMBINED WITH STRONG SUBSIDENCE CONTINUES TO DOMINATE THE GULF WITH A FEW AREAS OF STRATOCUMULUS CLOUDS OVER ERN HALF OF THE GULF AND MOSTLY CLEAR SKIES OVER THE REMAINDER OF THE GULF. FAIR WEATHER CONDITIONS WILL CONTINUE THROUGH SATURDAY. A COLD FRONT WILL MOVE INTO THE NW GULF LATE SUNDAY WITH GALE CONDITIONS EXPECTED IN THE WRN BAY OF CAMPECHE W OF THE FRONT LATE MONDAY. CARIBBEAN SEA... A WEAK STATIONARY FRONT IS ANALYZED ACROSS ERN CUBA INTO THE CARIBBEAN AS A SHEAR LINE AXIS EXTENDING FROM NEAR 20N77W TO THE SW CARIBBEAN NEAR 11N81W. ISOLATED SHOWERS ARE POSSIBLE OVER THE NW CARIBBEAN W OF THE SHEAR LINE...ESPECIALLY WITHIN 60 NM OFF THE COAST OF WRN PANAMA AND COSTA RICA. WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL ANTICYCLONIC CIRCULATION OVER CENTRAL AMERICA WHILE A NARROW UPPER TROUGH MOVING ACROSS THE FAR ERN CARIBBEAN. THESE TWO FEATURES ARE PROVIDING DRY STABLE AIR ALOFT AND STRONG SUBSIDENCE TO ALMOST THE ENTIRE DISCUSSION AREA. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA TO ACROSS COSTA RICA ALONG 10N...AND IS POSSIBLY GENERATING ISOLATED SHOWERS WITHIN 75 NM ALONG THE COAST OF COLOMBIA. A SLOW MOVING SURFACE TROUGH IS JUST A FEW MILES E OF THE LESSER ANTILLES GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS E OF 65W S OF 15N. THE SHEAR LINE WILL DISSIPATE LATE TONIGHT WHILE THE SURFACE TROUGH LINGERS OVER THE LESSER ANTILLES THROUGH MONDAY. ATLANTIC OCEAN... AN UPPER TROUGH IS MOVING OFF THE ERN CONUS SEABOARD INTO THE W ATLC N OF 24N W OF 72W WITH A RE-INFORCING SHOT OF COLD AIR OVER THIS AREA. A WEAKENING STATIONARY FRONT REMAINS UNSUPPORTED OVER THE W ATLC GENERATING ISOLATED SHOWERS WITHIN 20 NM ON EITHER SIDE OF THE FRONT ANALYZED FROM 29N70W CONTINUING SW ACROSS THE S BAHAMA ISLANDS NEAR 23N74W INTO ERN CUBA ALONG 20N77W. A NARROWING UPPER LEVEL TROUGH IS IN THE W/CENTRAL ATLC SUPPORTS A WEAK COLD FRONT EXTENDING FROM A 1006 MB SURFACE LOW NEAR 36N61W TO 30N60W TO 22N61W. NO CONVECTION IS ASSOCIATED WITH THIS FRONT. A SURFACE TROUGH IS JUST E OF THE LESSER ANTILLES ANALYZED FROM 19N58W TO W OF TRINIDAD AND TOBAGO NEAR 10N62W WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 120/150 NM EITHER SIDE OF THE TROUGH AXIS. AN UPPER TROUGH COVERS THE ERN ATLC N OF 25N E OF 40W SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N22W TO 27N30W. SCATTERED SHOWERS ARE WITHIN 30 NM SE OF THE FRONT. THE REMAINDER OF THE ATLC IS DOMINATED BY A NARROW HIGH AMPLITUDE UPPER RIDGE CENTERED OVER 40N36W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA