000 AXNT20 KNHC 231131 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST TUE FEB 23 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N12W 3N20W 1N30W 1N40W INTO NE BRAZIL NEAR 2S50W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE OF AXIS FROM 18W-27W. ...DISCUSSION... GULF OF MEXICO... AT 23/0900 UTC...A COLD FRONT CROSSES THE NORTH-CENTRAL PORTION OF THE FLORIDA PENINSULA ENTERING THE GULF REGION JUST N OF TAMPA BAY THEN CONTINUING ALONG 24N86W TO 22N94W. AT THIS POINT...THE FRONT BECOMES STATIONARY EXTENDING INTO NE MEXICO. BOTH SURFACE DATA AND AN EARLIER ASCAT PASS INDICATE THAT WINDS BEHIND THE FRONT HAS ALREADY BEGINNING TO VEER NE TO E ACROSS THE WESTERN GULF. A PRE-FRONTAL TROUGH IS ALSO ANALYZED ON THE 0900 UTC SURFACE MAP AND RUNS FROM 25N83W TO THE GULF OF HONDURAS NEAR 17N87W. CONVECTION NEAR THIS TROUGH HAS DIMINISHED DURING THE LAST FEW HOURS. THE FRONT WILL MOVE E OF THE AREA LATER TODAY AS HIGH PRES CONTINUES TO BUILD ACROSS THE GULF WATERS AND THE FLORIDA PENINSULA. A DEEP LAYER UPPER-LEVEL TROUGH EXTENDING FROM THE GREAT LAKES AREA TO THE SW CONUS SUPPORT THIS FRONT. A JET-STREAM BRANCH WITH CORE WINDS OF 130-150 KT CROSSES THE N GULF WATERS WITH A NEAR ZONAL WESTERLY FLOW DOMINATING THE UPPER LEVELS OVER THE GULF. WATER VAPOR IMAGERY SHOWS A BAND OF MID TO UPPER LEVEL MOISTURE STRETCHING FROM THE BAY OF CAMPECHE TO THE STRAITS OF FLORIDA THEN TURNING NE OVER THE WESTERN ATLC. MODERATE UPPER LEVEL SUBSIDENCE CAN BE FOUND TO THE NORTH OF THIS BAND. A REINFORCING AND MUCH STRONGER COLD FRONT WILL MOVE INTO THE NW GULF THIS EVENING. THEN...THE FRONT IS FORECAST TO MOVE ACROSS THE ERN GULF...THE YUCATAN PENINSULA AND MOST OF FLORIDA BY WEDNESDAY EVENING. STRONG TO GALE FORCE NLY WINDS WILL FOLLOW THE FRONT. ONCE AGAIN...HIGH PRES WILL BUILD ACROSS THE W GULF THU AND MOVE E FRI. CARIBBEAN SEA... AS PREVIOUSLY MENTIONED...A PRE-FRONTAL TROUGH ENTERS THE WESTERN CARIBBEAN SEA THROUGH THE YUCATAN CHANNEL THEN EXTENDS S TO THE GULF OF HONDURAS. THE REMNANTS OF A WEAK FRONTAL BOUNDARY IN THE FORM OF A SURFACE TROUGH IS JUST NORTH OF THE VIRGIN ISLANDS AND PUERTO RICO. THE SAN JUAN DOPPLER RADAR SHOWS A NARROW LINE OF SHOWERS ASSOCIATED WITH THIS TROUGH. A WEAK RIDGE DOMINATES THE REMAINDER OF THE BASIN. THE TRADES CONTINUE TO DIMINISH ACROSS THE AREA AND WINDS ARE VEERING TO THE SE AND S ACROSS THE CENTRAL AND WESTERN CARIBBEAN...FIRST DUE TO THE PRESENCE OF A COLD FRONT OVER THE SE GULF OF MEXICO AND SECOND THANKS TO THE DEVELOPMENT OF A WEAK LOW PRES OVER THE CENTRAL BAHAMAS. ALOFT...WLY FLOW DOMINATES THE ENTIRE AREA WITH MODERATE TO STRONG UPPER LEVEL SUBSIDENCE ACROSS THE EASTERN CARIBBEAN. A STRONG COLD FRONT IS FORECAST TO MOVE INTO THE NW CARIBBEAN LATE WED AND STALL FROM THE WINDWARD PASSAGE TO COSTA RICA THU AND FRI. NLY WINDS OF 20 TO 30 KT ARE EXPECTED BEHIND THE COLD FRONT. ATLANTIC OCEAN... A COLD FRONT ENTERS THE FORECAST AREA NEAR 31N78W THEN CONTINUES SW ACROSS N-CENTRAL FLORIDA INTO THE GULF OF MEXICO. SLY WINDS OF 20 TO 25 KT ARE SEEN JUST AHEAD OF THE FRONT PER THE LATEST ASCAT DATA. AT 23/0900 UTC...SURFACE DATA ACROSS THE BAHAMAS INDICATE THE DEVELOPMENT OF A WEAK SURFACE LOW IS...ANALYZED 1005 MB...NEAR 24N76W WITH A TROUGH EXTENDING WSW TO CENTRAL CUBA. THIS LOW IS FORECAST TO MOVE EWD TO A POSITION NEAR 24N64W IN ABOUT 24 HOURS DRAGGING A SURFACE TROUGH BEHIND IT ACROSS THE SRN BAHAMAS AND NORTHERN HISPANIOLA. THE REMNANTS OF A FRONT IN THE FORM OF A SURFACE TROUGH EXTENDS FROM THE CENTRAL ATLC TO JUST N OF PUERTO RICO AND THE VIRGIN ISLANDS. A WEAK 1016 HIGH PRES CENTERED NEAR 25N56W EXTENDS A RIDGE OVER THE W ATLC MAINLY E OF 75W. THIS FEATURE WILL WEAKEN IN ABOUT 24 HOURS AS THE LOW PRES OVER THE BAHAMAS MOVES EWD. A SECOND WEAK SURFACE RIDGE IS OVER THE E ATLC ANCHORED BY A 1019 MB HIGH NEAR 23N21W. ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE FORECAST REGION. UPPER DIFFLUENCE AHEAD OF A SHORT-WAVE TROUGH EXITING THE SE CONUS IS HELPING TO INDUCE AN AREA OF CLOUDINESS WITH EMBEDDED SHOWERS AND ISOLATED TSTMS BETWEEN 65W AND 75W. SIMILAR CONDITIONS ARE NOTED N OF 20N E OF 50W AHEAD OF AN UPPER-LEVEL TROUGH LOCATED OVER THE CENTRAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR