000 AXNT20 KNHC 250546 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N10W 3N19W 1N34W ACROSS THE EQUATOR NEAR 45N THEN INLAND OVER SOUTH AMERICA NEAR 1S49W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 90/120 NM OF THE ITCZ BETWEEN 12W-26W. ...DISCUSSION... GULF OF MEXICO... AT 25/0300 UTC...THE COLD FRONT HAS MOVED SE OF THE GULF REGION AND NOW HIGH PRES CENTERED OVER THE WESTERN GULF NEAR 23N97W DOMINATES THE MAJORITY OF THE AREA. STRONG NLY WINDS ARE NOTED OVER THE EASTERN HALF OF THE GULF IN THE WAKE OF THE COLD FRONT CURRENTLY MOVING ACROSS WESTERN CUBA. CONVECTIVE CLOUDS STREETS ARE FORMING PARALLEL TO THE WINDS DUE TO THE ADVECTION OF COLD AIR OVER RELATIVELY WARM WATERS. HIGH PRES WILL MOVE EWD 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 FOLLOW THE FRONT. A LOW MAY FORM ALONG THE FRONTAL BOUNDARY OVER THE N GULF WATERS EARLY SATURDAY. A DEEP LAYER TROUGH EXTENDING FROM THE GREAT LAKES AREA TO THE NW PORTION OF THE GULF SUPPORTS THE AFOREMENTIONED 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 SOUTH FLORIDA AND THE W ATLC. MODERATE TO STRONG SUBSIDENCE IS NOTED NW OF LINE FROM TAMPA BAY FLORIDA TO TUXPAN MEXICO. CARIBBEAN SEA... A COLD FRONT EXTENDS FROM WESTERN CUBA TO NEAR GUATEMALA/ HONDURAS BORDER. NW WINDS OF 20 TO 30 KT ARE OBSERVED BEHIND THE FRONT INCLUDING THE YUCATAN CHANNEL. A PRE-FRONTAL TROUGH IS ANALYZED FROM CENTRAL CUBA TO NE HONDURAS. AN AREA OF MODERATE TO STRONG CONVECTION IS WITHIN 180 NM AHEAD OF THE TROUGH AXIS N OF 18N. PART OF THIS ACTIVITY IS AFFECTING EASTERN CUBA AND THE CAYMAN ISLANDS WHERE SOME SHOWERS AND TSTMS HAVE BEEN REPORTED. ANOTHER AREA OF MODERATE CONVECTION IS NOTED NEAR THE SOUTHERN END OF THE TROUGH AXIS OVER HONDURAS. A DIFFLUENT PATTERN ALOFT BETWEEN THE UPPER-LEVEL TROUGH ACROSS THE NW GULF OF MEXICO AND AN UPPER-LEVEL HIGH CENTERED OVER COLOMBIA IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. DUE TO THE PRESENCE OF THE COLD FRONT AND THE PRE-FRONTAL TROUGH OVER THE WESTERN CARIBBEAN...THE TRADE WINDS CONTINUE TO ABATE PARTICULARLY OVER THE CENTRAL PORTION OF THE BASIN WITH ELY WINDS OF 10 TO 15 KT OVER 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 THIS AFTERNOON THEN WILL CROSS HISPANIOLA TONIGHT AFFECTING PUERTO RICO ON FRI. A SURFACE TROUGH...REMNANTS OF AN OLD FRONTAL BOUNDARY EXTENDS FROM A 1008 MB LOW PRES LOCATED NEAR 22N57W TO THE N LEEWARD ISLANDS AND PUERTO RICO INCLUDING ALSO THE UK/US VIRGIN ISLANDS. A NARROW BAND OF LOW TO MID CLOUDS WITH EMBEDDED SHOWERS IS ASSOCIATED WITH THIS TROUGH. THE LOW PRES WILL MOVE EWD DRAGGING THE TROUGH AWAY FROM THIS AREA LATE TODAY. ATLANTIC OCEAN... A COLD FRONT EXTENDS FROM A 1002 MB LOW PRES LOCATED NEAR 30N77W ACROSS THE WESTERN BAHAMAS TO WESTERN CUBA. AN AREA OF SHOWERS WITH EMBEDDED TSTMS IS SEEN AHEAD OF THE FRONT OVER THE CENTRAL BAHAMAS AND ADJACENT COASTAL WATERS. BREEZY AND CLOUDY CONDITIONS ARE PRESENTLY PREVAILING OVER SOUTH FLORIDA BUT A MARKED IMPROVEMENT IN CLOUD COVER SHOULD BE EXPECTED TOWARD THE MORNING HOURS. A COLDER NIGHT IS IN STORE FOR SOUTH FLORIDA TONIGHT. A WEAK 1014 MB HIGH IS AHEAD OF THE FRONT NEAR 27N64W. THIS SYSTEM WILL DISSIPATE DURING THE NEXT 24 HOURS AS THE FRONT CONTINUES TO MOVE SE ACROSS THE SW N ATLC INCLUDING THE BAHAMAS. A 1006 MB LOW PRES IS NEAR 32N57W WITH A TROUGH EXTENDING TO ANOTHER LOW PRES SYSTEM LOCATED NEAR 22N57W. SEE THE CARIBBEAN SECTION FOR MORE DETAILS. AN ASCAT PASS FROM 0030 UTC SHOWED VERY WELL THE CYCLONIC CIRCULATION ASSOCIATED WITH THE LOW NEAR 32N57W. A BROAD BUT WEAK SURFACE RIDGE EXTENDS FROM OVER THE E ATLC INTO THE REMAINDER OF THE CENTRAL ATLC ANCHORED BY A 1021 MB HIGH CENTERED JUST W OF THE CANARY ISLANDS NEAR 27N19W. THIS FEATURE WILL MOVE NE IN THE NEXT 24 HOURS. ALOFT...A RIDGE/ TROUGH/RIDGE PATTERN DOMINATES THE FORECAST AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR