000 AXNT20 KNHC 120004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED JAN 11 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ANALYZED ACROSS AFRICA ENTERING THE E TROPICAL ATLC NEAR 10N13W TO 9N16W. THE ITCZ CONTINUES FROM 9N16W ALONG 3N32W 1N39W ACROSS THE EQUATOR INTO SOUTH AMERICA NEAR 50W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 1N-3N BETWEEN 25W-33W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW IS MOVING NE OVER THE MOUNTAINS OF TENNESSEE WITH THE UPPER TROUGH EXTENDING OVER THE GULF N OF 25N SUPPORTING A COLD FRONT THAT AT 11/2100 UTC EXTENDS ACROSS THE FLORIDA PENINSULA BETWEEN ST. AUGUSTINE AND FORT MYERS THEN THROUGH THE YUCATAN CHANNEL INTO THE NW CARIBBEAN NEAR 22N86W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE E OF THE FRONT S OF 23N TO OVER S FLORIDA AND W CUBA. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE AND DRY STABLE AIR IS MOVING OVER THE GULF W OF THE FRONT WITH CLEARING SKIES AND A WEAK 1013 MB HIGH OVER THE SE GULF NEAR 23N93W. THE COLD FRONT WILL REACH THE FAR SE WATERS EARLY TONIGHT WHERE IT WILL STALL AND WEAKEN INTO THU EVENING. A SECOND STRONGER COLD FRONT WILL MOVE INTO THE NW GULF LATE TONIGHT/EARLY THU AND MOVE QUICKLY ACROSS THE GULF EXITING BY LATE FRI. HIGH PRESSURE WILL THEN BUILD ACROSS THE GULF THROUGH SUN AND SHIFTING EASTWARD LATE SUN AND MON. CARIBBEAN SEA... THE FRONT OVER THE SE GULF OF MEXICO EXTENDS OVER THE NW CARIBBEAN AT 11/2100 UTC THROUGH THE YUCATAN CHANNEL NEAR 22N86W TO INLAND OVER THE YUCATAN PENINSULA NEAR 20N87W CONTINUING W TO OVER S MEXICO. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 45 NM E OF THE FRONT OVER THE CARIBBEAN WATERS. A BROAD UPPER RIDGE COVERS THE CARIBBEAN WITH THE AXIS ALONG EXTENDING FROM THE E VENEZUELA OVER THE LESSER ANTILLES INTO THE W ATLC. WATER VAPOR IMAGERY INDICATES MOSTLY DRY STABLE AIR ACROSS THE REGION. HOWEVER...LOW LEVEL MOISTURE IS GENERATING ISOLATED SHOWERS WITHIN 90 NM OF LINE FROM E CUBA NEAR 20N76W TO OVER E HONDURAS NEAR 15N84W INCLUDING JAMAICA. THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING FAIR WEATHER CONDITIONS AGAIN THIS EVENING. THE COLD FRONT WILL WEAKEN AS IS MOVES ACROSS THE NW CARIBBEAN TONIGHT AND SLOWLY DISSIPATE THROUGH FRI. WEAK HIGH PRESSURE N OF THE AREA WILL SHIFT EASTWARD TONIGHT. A STRONGER COLD FRONT WILL ENTER THE NW CARIBBEAN SAT FOLLOWED BY BUILDING HIGH PRESSURE. ATLANTIC OCEAN... THE UPPER TROUGH OVER THE GULF OF MEXICO EXTENDS INTO THE W ATLC N OF 26N W OF 76W SUPPORTING THE COLD FRONT THAT AT 11/2100 UTC ENTERS THE ATLC OFF THE GEORGIA COAST NEAR SAVANNAH TO ACROSS THE FLORIDA PENINSULA NEAR ST. AUGUSTINE CONTINUING INTO THE GULF OF MEXICO AND NW CARIBBEAN. SHOWERS/THUNDERSTORMS ARE N OF THE DISCUSSION AREA WITH ISOLATED SHOWERS WITHIN 75 NM OF LINE FROM 29N77W TO ACROSS S FLORIDA AND THE STRAITS OF FLORIDA NEAR FORT LAUDERDALE INCLUDING THE N BAHAMA ISLANDS. THE BROAD UPPER RIDGE THAT COVERS THE CARIBBEAN COVERS THE W ATLC INTO THE CENTRAL ATLC W OF 50W WITH MOSTLY FAIR CONDITIONS AND A 1018 MB HIGH NEAR 26N66W. HOWEVER...LOW LEVEL MOISTURE TO THE W OF THE SURFACE HIGH IS GENERATING ISOLATED SHOWERS WITHIN 90 NM OF LINE FROM 28N70W TO ACROSS E CUBA NEAR 20N76W. A BROAD UPPER TROUGH DIPS S INTO THE CENTRAL ATLC AND E ATLC TO 20N BETWEEN 25W-50W SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N50W EXTENDING ALONG 26N62W THEN NW OUT OF THE REGION NEAR 32N70W. A SURFACE TROUGH EXTENDS FROM 29N54W TO 20N56W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE WITHIN 60 NM OF LINE FROM 27N50W TO BEYOND 32N46W. THIS UPPER TROUGH IS ALSO SUPPORTING A STATIONARY FRONT THAT EXTENDS TO 32N36W WHERE A SURFACE TROUGH CONTINUES ALONG 27N36W TO 21N38W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 25N-29N BETWEEN 32W-35W. A WEAK SURFACE RIDGE COVERS THE REMAINDER OF THE E ATLC. THE COLD FRONT MOVING OFF THE GEORGIA COAST WILL REACH FROM 31N75W TO W CUBA THU THEN BEGIN TO WEAKEN AS IT REACHES FROM 31N71W TO CENTRAL CUBA THU NIGHT. A STRONGER COLD FRONT WILL MOVE OFF THE SE U.S. COAST THU NIGHT AND REACH FROM 31N72W TO W CUBA FRI AND FROM BERMUDA TO E CUBA SAT THEN WEAKEN AND STALL ON SUN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW