000 AGXX40 KNHC 210716 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 217 AM EST SAT JAN 21 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... MODERATE SOUTHERLY RETURN FLOW CONTINUES TO DOMINATE THE GULF ACCORDING TO THE LATEST SURFACE OBSERVATIONS. THE NEXT COLD FRONT WILL APPROACH THE COAST OF TEXAS THIS AFTERNOON...BUT STALLS SAT EVENING AS THE RIDGE BEGINS TO BUILD TO ITS S AND PUSHES THE WEAKENING FRONT N OF THE AREA. OVERALL...THERE IS GOOD AGREEMENT AMONG THE 00Z MODELS WITH THIS FRONT. DIFFERENCE COME IN TO PLAY ON SUN WHEN THE NEXT COLD FRONT DIVES S THROUGH THE SOUTHERN U.S. PLAINS. THE 6- AND 12-HOUR TRENDS IN THE GFS ARE TOWARD A SLOWER SOLUTION WITH THIS COLD FRONT LIKE THE MORE CONSISTENT 00Z ECMWF. WHILE THE DIFFERENCES BETWEEN THE 00Z GFS AND ECMWF ARE NOT AS GREAT AS THEIR RESPECTIVE RUNS 24 HOURS AGO...THE ECMWF CONTINUES TO BE SLOWER TO CARRY THE FRONT OFF THE TEXAS COAST AND WEAKER WITH THE WINDS NEAR THE FRONT THAN THE GFS. WILL CONTINUE TO HEDGE TOWARD THE ECMWF HERE. THIS FRONT WILL WASH OUT OVER THE NORTHERN HALF OF THE FL PENINSULA TUE EVENING AND SOUTHERLY RETURN FLOW WILL AGAIN COVER THE GULF. AN UPPER LOW PASSING THROUGH THE SW U.S. AND NORTHERN MEXICO WILL APPROACH THE GULF OF WED. THE GFS BECOMES THE WEAKEST OF THE GLOBAL MODELS WITH UPPER LOW BY WED EVENING WHILE THE UKMET AND ECMWF ARE IN BETTER AGREEMENT ON THE STRENGTH OF THE LOW. A BLEND OF THE UKMET AND ECMWF IS CLOSEST TO THE MODEL CONSENSUS AND WILL BE USED FOR THE DAY 5 FORECAST. SOUTHWEST N ATLC S OF 31N W OF 55W AND TROPICAL N ATLC... HIGH PRES NEAR BERMUDA WILL LINGER THROUGH THE WEEKEND. A COLD FRONT OVER THE CAROLINAS WELL N OF THE AREA IS INCREASING THE PRES GRADIENT OVER NW WATERS AS IT THE FRONT PASSES N OF THE HIGH. SOUTHERLY RETURN FLOW WILL BRIEFLY BECOME FRESH OVER NW WATERS UNTIL THE FRONT PASSES WELL NE SUN. THE 00Z GFS AND ECMWF ARE IN AGREEMENT ON THIS FORECAST. THE NEXT FRONT WILL BEGIN TO APPROACH FROM THE W ON MON. THE FORECAST THINKING IS TO LEAN TOWARD THE SLOWER ECMWF SOLUTION WITH THIS SYSTEM. THIS LOGIC IS EXPLAINED IN THE GULF OF MEXICO SECTION. FRESH TRADE WINDS ARE EXPECTED TO RETURN S OF 24N THU AS HIGH PRES BUILDS BEHIND THE FRONT. THE LARGE NE TO N SWELLS OVER TROPICAL N ATLC ZONE YESTERDAY HAVE BEGUN TO SUBSIDE...BUT SEAS TO 8 FT WILL LINGER OVER WATERS S OF 18N THROUGH MON AS FRESH TRADE WINDS CONTINUE TO CONTRIBUTE TO THE SWELL. THE SUBTROPICAL HIGH WILL WEAKEN AS THE LEADING EDGE OF THE COLD FRONT OVER FL APPROACHES IT ON TUE....ALLOWING TRADE WINDS TO DIMINISH AND SEAS TO SUBSIDE BELOW 8 FT. CARIBBEAN SEA... THE WINDSAT PASS FROM 2250 UTC SHOWED WINDS TO 30 KT ALONG THE COAST OF COLOMBIA AND THE 0216 UTC JASON1 PASS SHOWED SEAS TO 11 FT. MORE RECENTLY...SHIPS PHET AND LAOX5 HAVE CONFIRMED WINDS JUST BELOW GALE FORCE NEAR COLOMBIA AND SEAS TO 15 FT. THE 0228 UTC ASCAT PASS ALSO SHOWED WINDS TO 30 KT ALONG THE S COAST OF THE DOMINICAN REPUBLIC. THESE STRONG WINDS ARE DRIVEN BY THE PRES GRADIENT BETWEEN THE BERMUDA HIGH AND LOWER PRES OVER COLOMBIA. FRESH WINDS ALSO EXTEND INTO THE EASTERN CARIBBEAN. THE COLD FRONT PASSING THROUGH THE GULF OF MEXICO WILL BEGIN TO SHOVE THE SUBTROPICAL HIGH NE MON...WEAKENING THE TRADE WINDS SLIGHTLY BEFORE THEY INTENSIFY FURTHER ON TUE AND WED AS HIGH PRES BUILDS BEHIND THE COLD FRONT. THE SLOWER ECMWF TIMING IS PREFERRED WITH THIS COLD FRONT TO THE N AND ITS IMPACTS ON THE SUBTROPICAL HIGH. THIS FORECAST REASONING IS EXPLAINED IN THE GULF OF MEXICO SECTION. WARNINGS... GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER