000 AGXX40 KNHC 150748 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 248 AM EST SAT JAN 15 2011 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... 1030 MB HIGH PRES CENTER PERSISTED TONIGHT NEAR THE ALABAMA/MISSISSIPPI BORDER NEAR 33N89W WITH COOL AIR CONTINUING TO SPILL INTO THE E HALF OF THE GULF AND ACROSS MUCH OF FLORIDA. RETURN FLOW ACROSS THE W AND NW PORTIONS WAS PRODUCING WIDESPREAD LOW AND AND MIDDLE LAYER CLOUDINESS AND LIGHT TO MODERATE RAIN AND SHOWERS FROM FAR NE MEXICO ACROSS THE SE HALF OF TEXAS AND ACROSS THE COASTAL WATERS. A RECENT 0346 UTC ASCAT PASS SHOWED SELY WINDS 20-25 KT ACROSS THE NW GULF N OF 25N AND W OF 92W...WHILE BUOY 42020 OFF THE SE TEXAS COAST HAS RISEN TO 7-8 FT DURING THE PAST COUPLE OF HOURS. ALSO...A LLVL TROF OR CONVERGENCE LINE HAS BEGUN TO DEVELOP ACROSS THE SE GULF AND WILL DRIFT SLOWLY NW THROUGH SUN BEFORE LIFTING OUT AND DISSIPATING. THIS BOUNDARY WILL ACT AS A FOCUS FOR CLOUDS AND SHOWERS ON THE NW FLANK. OTHERWISE...RETURN FLOW WILL PERSIST IN THE W GULF THROUGH SUN MORNING AS THE HIGH WEAKENS AND DRIFTS SE. A DEVELOPING COLD FRONT IS EXPECTED TO APPROACH THE NW GULF FROM E TEXAS SUN MORNING AND PUSH E AND OFFSHORE SUN NIGHT WITH A N TO S ALIGNED FRONT SWEEPING ACROSS THE GULF THROUGH TUE MORNING. THE GLOBAL MODELS...UKMET...ECMWF...AND GFS ARE STILL DEPICTING DIFFERING SOLUTIONS WITH THIS FEATURE...BUT ARE GRADUALLY COMING INTO CLOSER AGREEMENT WITH THE UKMET NOW FASTEST BY TUE. A SURFACE LOW PREVIOUSLY FORECAST TO DEVELOP NOW IS SUGGESTED TO REMAIN OVER LAND BEFORE EMERGING OVER THE ATLC TUE. THE LINGERING CONVERGENCE LINE AHEAD OF THE FRONT MAY ALLOW FOR A NEGATIVE TILT TROUGH AHEAD OF THE FRONT MON AND SE WINDS TO 20 KT ACROSS THE NE GULF. THE FRONT WILL REACH FROM NEAR THE LOUISIANA/TEXAS BORDER TO JUST N OF THE BAY OF CAMPECHE MON MORNING THEN FROM THE FLORIDA BIG BEND TO NEAR THE YUCATAN PENINSULA TUE MORNING THEN PUSHING E OF THE AREA TUE NIGHT. HIGH PRES BUILDS IN WED WITH RETURN FLOW RETURNING IN THE W GULF LATE WED. SW N ATLC S OF 31N W OF 55W... OLD FRONTAL BOUNDARY WAS STRUNG OUT ACROSS THE SW AND CENTRAL N ATLC OVERNIGHT HAS TRANSITIONED TO A SHEAR LINE FROM NEAR 25.5N65W SW THROUGH THE TURKS AND CAICOS ACROSS ERN CUBA AND ACROSS THE NW CARIB. A 0204 UTC ASCAT PASS SHOWED NE WINDS 20-25 KT N OF THE SHEAR LINE BETWEEN 65W AND 70W WITH A SMALL AREA OF 25-30 KT...WHILE DOWNWIND SHIP OBS ALSO REPORTED 20-25 KT JUST NE OF THE TURKS AND CAICOS. THIS FRESH FLOW CONTINUED THROUGH THE CENTRAL BAHAMAS AND STRAITS OF FLORIDA AND WAS AFFECTING US HERE IN EXTREME SE FLORIDA AS WELL. MODELS SHOW SE LLVL FLOW INCREASING ACROSS THE ATLC E OF 65W AND FORCING THIS OLD BOUNDARY SLOWLY NW OVER THE NEXT COUPLE OF DAYS...TRANSITIONING INTO A WARM FRONT ALONG 28N E OF 70W BY 48 HOURS. THE WEAKENING HIGH ACROSS THE SE U.S. WILL IN TURN WEAKEN THE PRES GRADIENT N OF THE CURRENT SHEAR LINE...AND WINDS N OF THIS BOUNDARY ARE EXPECTED TO DIMINISH BELOW 20 KT BY SUN AFTERNOON AS IT DRIFTS NW AND WASHES OUT. SE-S RETURN FLOW WILL BECOME ESTABLISHED ACROSS THE MAJORITY OF THE WATERS AHEAD OF THE GULF OF MEXICO FRONTAL SYSTEM MON. WINDS BECOME S-SW AND INCREASE TO 20 KT N OF 27N AHEAD OF THE FRONT EARLY TUE WITH WINDS SHIFTING TO THE W-NW AT 15-20 KT BEHIND THE FRONT. THE FRONT WILL REACH FROM NEAR 31N77W TO SE FLORIDA TUE NIGHT THEN FROM NEAR BERMUDA TO THE TURKS AND CAICOS WED NIGHT AS RIDGING BUILDS IN FROM THE CAROLINAS. CARIBBEAN SEA AND TROPICAL N ATLC... SHEAR LINE NOW FROM ERN CUBA SW TO JUST W OF JAMAICA THEN IS ILL DEFINED TO THE E COAST OF NICARAGUA. NE WINDS 20-25 KT WILL CONTINUE TO THE NW OF THIS BOUNDARY THROUGH SUN MORNING BEFORE DIMINISHING AS GRADIENT WEAKENS. TRADES HAVE BEEN GRADUALLY DIMINISHING ACROSS THE REMAINDER OF THE CARIB PAST 24 HOURS BUT WILL STRENGTHEN AGAIN E OF 70W SUN NIGHT AND MON AS HIGH PRES BUILDS FROM CENTRAL ATLC WWD. THIS TOO ALSO AFFECT THE TOPICAL N ATLC WATERS...WERE SEAS ARE EXPECTED TO BUILD SLIGHTLY TO 9-11 FT BY MON...WITH SEAS DOMINATED BY NE TRADE WIND SWELL. LITTLE CHANGE THERE THROUGH EARLY WED. WARNINGS.. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING