000 AXNT20 KNHC 212344 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED DEC 20 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 2335 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS INLAND OVER W AFRICA TO THE COAST OF SIERRA LEONE NEAR 8N12W QUICKLY ENDING AT 7N15W. THE ITCZ CONTINUES FROM 7N15W ALONG 5N22W 6N31W 4N40W TO 6N48W. SCATTERED WEAK TO ISOLATED MODERATE CONVECTION IS WITHIN 100 NM EITHER SIDE OF THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... THE COLD FRONT THAT WAS MOVING ACROSS THE NW AND N-CENTRAL GULF EARLIER TODAY IS NOW ANALYZED AS STATIONARY EXTENDING SW FROM THE COAST OF ALABAMA NEAR 30N88W TO A WEAK 1011 MB LOW NEAR 25N97W THEN S TO NEAR 22N96W BECOMING A WEAK SURFACE TROUGH TO THE COAST OF MEXICO NEAR 19N96W. DOPPLER RADAR IMAGERY INDICATES AN AREA OF WIDESPREAD SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT IMPACTING THE NE CORNER OF THE GULF N OF 28N BETWEEN 84W-90W. A A NARROW LINE OF SHOWERS IS ALONG THE FRONT AXIS S OF 28N. NE WINDS UP TO 15 KTS ARE N OF THE FRONT WITH MOSTLY RETURN FLOW 10-15 KTS ACROSS THE REMAINDER OF THE BASIN. THE REMAINDER OF THE BASIN IS COVERED BY DRY AIR ALOFT WHICH IS HELPING PROVIDE FAIR CONDITIONS ACROSS MUCH OF THE SRN GULF. EXPECT A SECOND UPPER LEVEL PUSH OF ENERGY TO INTRODUCE ANOTHER COLD FRONT INTO THE NW GULF TOMORROW. CARIBBEAN SEA... ENE TRADEWIND FLOW 20-30 KTS IS OVER A GREAT PART OF THE ERN... CENTRAL...AND SW CARIBBEAN...REACHING ABOVE GALE FORCE CRITERIA NEAR THE COASTAL WATERS OF COLOMBIA. LITTLE CLUSTERS OF SHOWERS ARE EMBEDDED WITHIN THE TRADEWIND FLOW WITH MORE CONCENTRATED ACTIVITY OVER THE S-CENTRAL CARIBBEAN S OF 14N BETWEEN 66W-74W. SIMILAR CONVECTION IS OVER THE IMMEDIATE COASTAL WATERS OF WRN PANAMA AND COSTA RICA DUE TO THE MONSOON TROUGH EXTENDING INLAND ACROSS PANAMA TO NRN COLOMBIA. SURFACE HIGH PRESSURE OVER THE W ATLC IS EXPECTED TO REMAIN STATIONARY WHICH WILL CAUSE THE STRONG PRESSURE GRADIENT...AND THUS HIGH WINDS...TO PERSIST OVER THE CARIBBEAN FOR THE NEXT COUPLE DAYS. ATLANTIC OCEAN... BROAD SURFACE RIDGING AROUND A 1027 MB HIGH NEAR 31N64W IS PROVIDING MOSTLY FAIR WEATHER ACROSS THE WRN ATLC. AN UPPER LEVEL TROUGH MOVING ACROSS THE CENTRAL ATLC CONTINUES TO SUPPORT A FRONTAL BOUNDARY IN THE CENTRAL ATLC ANALYZED INTO THE DISCUSSION AREA AS STATIONARY ALONG NEAR 31N38W EXTENDING SW ALONG 25N40W BECOMING A DISSIPATING COLD FRONT TO 17N53W. ISOLATED SHOWERS ARE ONLY WITHIN 30 NM EITHER SIDE OF THE FRONTAL AXIS. FARTHER S...AN AREA OF ACTIVE WEATHER IS JUST E OF THE SRN WINDWARD ISLANDS FROM 10N-12N BETWEEN 53W-62W DUE TO WIND SPEED CONVERGENCE AROUND A SHEAR LINE AXIS ANALYZED FROM 13N53W TO 10N60W. THE REMAINDER OF THE BASIN IS INFLUENCED BY STRONG SURFACE RIDGING AROUND A 1035 MB HIGH NEAR 44N12W PROVIDING GENERALLY FAIR WEATHER ACROSS THE ERN ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA