000 AXNT20 KNHC 251134 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST THU FEB 25 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 7N11W 4N24W CROSSING THE EQUATOR AT 38W THEN INLAND OVER NE BRAZIL NEAR 1S50W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 140 NM S OF AXIS E OF 20W. ...DISCUSSION... GULF OF MEXICO... HIGH PRES CONTINUES TO BUILD ACROSS THE GULF REGION IN THE WAKE OF A STRONG COLD FRONT CURRENTLY MOVING OVER EASTERN CUBA. FRESH TO STRONG NLY WINDS ARE STILL NOTED OVER MOST OF THE AREA PER SURFACE DATA AND A RECENT ASCAT PASS. CONVECTIVE CLOUDS STREETS ARE FORMING PARALLEL TO THESE WINDS DUE TO THE ADVECTION OF COLD AIR OVER RELATIVELY WARM WATERS. CLEARING IS ALREADY OCCURRING OVER THE N WATERS PARTICULARLY N OF 28N. HIGH PRES WILL MOVE EWD TODAY ALLOWING SLY RETURN FLOW TO SET UP OVER THE WESTERN GULF THIS EVENING AHEAD OF THE NEXT COLD FRONT EXPECTED TO PUSH SE OFF THE COAST OF TEXAS FRI AFTERNOON. NLY WINDS OF 20 TO 30 KT WILL ALSO FOLLOW THE NEW COLD FRONT. A LOW MAY DEVELOP ALONG THE FRONTAL BOUNDARY OVER THE N GULF WATERS EARLY SATURDAY AND MOVE EWD TOWARD THE FLORIDA PENINSULA LATE SAT. A DEEP LAYER TROUGH EXTENDING FROM THE GREAT LAKES REGION TO THE NW PORTION OF THE GULF SUPPORTS THE ABOVE MENTIONED COLD FRONT. SWLY WINDS AHEAD OF THIS UPPER-LEVEL TROUGH ARE ADVECTING MID TO UPPER LEVEL MOISTURE FROM THE EPAC ACROSS SOUTHERN MEXICO AND THE YUCATAN PENINSULA INTO SE FLORIDA AND THE W ATLC. MODERATE TO STRONG SUBSIDENCE IS NOTED OVER MUCH OF THE GULF. CARIBBEAN SEA... AT 25/0900 UTC...A COLD FRONT EXTENDS FROM EASTERN CUBA...NEAR THE CITY OF CAMAGUEY TO NE HONDURAS. NW WINDS OF 20 TO 30 KT ARE OBSERVED OVER THE WESTERN CARIBBEAN BEHIND THE FRONT INCLUDING THE YUCATAN CHANNEL. A PRE-FRONTAL TROUGH IS ANALYZED FROM NEAR SANTA CRUZ DEL SUR CAMAGUEY TO NEAR 13N82W. A BAND OF SHOWERS AND TSTMS IS WITHIN AROUND 90 NM JUST AHEAD OF THE TROUGH AXIS N OF 17.5N. PART OF THIS CONVECTIVE ACTIVITY IS AFFECTING EASTERN CUBA AND THE WESTERN PORTION OF JAMAICA. MONTEGO BAY REPORTED +TSRA WITH GUSTY WINDS OF 31 KT. CONVECTION NEAR THE SOUTHERN END OF THE TROUGH AXIS OVER HONDURAS HAS DIMINISHED...AND NOW SOME SHOWERS WITH ISOLATED TSTMS ARE DEVELOPING OVER CENTRAL NICARAGUA. A DIFFLUENT PATTERN ALOFT BETWEEN THE UPPER-LEVEL TROUGH ACROSS THE NW GULF OF MEXICO AND AN UPPER-LEVEL HIGH CENTERED OVER COLOMBIA EXTENDING A RIDGE NWD ALONG 69W-70W IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. DUE TO THE PRESENCE OF THE COLD FRONT AND THE PRE-FRONTAL TROUGH OVER THE WESTERN- CENTRAL CARIBBEAN...THE TRADE WINDS CONTINUE TO ABATE MAINLY NEAR THE COAST OF COLOMBIA WHERE ONLY NE WINDS OF 10 KT ARE SEEN. ELY WINDS OF 10 TO 15 KT ARE BLOWING ACROSS THE EASTERN CARIBBEAN. THE COLD FRONT AND THE PRE-FRONTAL TROUGH WILL MERGE AND THE COLD FRONT WILL MOVE TO A POSITION FROM THE WINDWARD PASSAGE TO COSTA RICA EARLY THIS AFTERNOON THEN WILL CROSS HISPANIOLA THIS EVENING AND TONIGHT AFFECTING PUERTO RICO ON FRI. A SURFACE TROUGH... REMNANTS OF AN OLD FRONTAL BOUNDARY EXTENDS FROM A 1009 MB LOW PRES LOCATED NEAR 22N56W TO NEAR ANTIGUA IN THE LEEWARD ISLANDS. A NARROW BAND OF LOW TO MID CLOUDS WITH EMBEDDED SHOWERS IS ASSOCIATED WITH THIS TROUGH. THE LOW PRES WILL MOVE EWD AND DISSIPATE DRAGGING THE TROUGH AWAY FROM THIS AREA LATE TODAY. ATLANTIC OCEAN... A COLD FRONT ENTERS THE FORECAST REGION NEAR 31N74W THEN CONTINUES SW ACROSS THE CENTRAL BAHAMAS AND EASTERN CUBA INTO THE CARIBBEAN SEA. HIGH PRES BUILDING OVER THE FLORIDA PENINSULA AND THE NW BAHAMAS WILL BRING WITH IT MUCH COLDER TEMPERATURES THROUGH FRIDAY. THE AREA OF SHOWERS WITH EMBEDDED TSTMS THAT WAS PREVIOUSLY AFFECTING THE CENTRAL BAHAMAS HAS MOVED EWD AHEAD OF THE FRONT AND NOW COVERS THE REGION FROM 24N-25.5N BETWEEN 71W AND 73W. A WEAK 1015 MB HIGH IS EAST OF THE FRONT NEAR 25N64W. THIS SYSTEM WILL DISSIPATE DURING THE NEXT 24 HOURS AS THE FRONT CONTINUES TO MOVE SE ACROSS THE SW N ATLC AND THE SE BAHAMAS. A 1004 MB LOW PRES IS NEAR 31N55W WITH A TROUGH EXTENDING TO ANOTHER LOW PRES SYSTEM LOCATED NEAR 22N56W. SEE THE CARIBBEAN SECTION FOR MORE DETAILS. A MUCH EARLIER ASCAT PASS SHOWED VERY WELL THE CYCLONIC CIRCULATION ASSOCIATED WITH THE LOW NEAR 31N55W WHICH IS FORECAST TO MOVE ESE TO NEAR 28N31W IN ABOUT 24 HOURS. THE GFS COMPUTER MODEL SUGGESTS SW TO W WINDS NEAR GALE FORCE ASSOCIATED WITH THIS DEEPENING LOW PRES THAT WILL APPROACH THE MADEIRA AND CANARY ISLANDS LATE FRI. A BROAD BUT WEAK SURFACE RIDGE EXTENDS FROM OVER THE E ATLC INTO THE REMAINDER OF THE CENTRAL ATLC ANCHORED BY A 1017 MB HIGH CENTERED JUST W OF THE CANARY ISLANDS NEAR 26N21W. THIS FEATURE WILL MOVE NE IN THE NEXT 24 HOURS. IN THE UPPER LEVELS...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE FORECAST AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR