000 AGXX40 KNHC 180706 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EST FRI NOV 18 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... FRESH TO STRONG NE WINDS ARE NOTED ACROSS MOST OF THE GULF THIS MORNING...N OF A WEAKENING COLD FRONT THAT EXTENDS FROM S FLORIDA TO NW YUCATAN...AND INTO THE FAR SW GULF. WINDS ARE ALREADY STARTING TO DIMINISH OVER THE NW GULF AS HIGH PRES BUILDS N OF THE AREA. BUOY OBSERVATIONS INDICATE SEAS ARE AT LEAST 8 FT OVER MUCH OF THE SOUTHERN HALF OF THE GULF...AND THIS WILL SUBSIDE THROUGH TODAY AS WINDS DIMINISH SLIGHTLY AS THE FRONT MOVES INTO THE FAR SE GULF AND BECOMES DIFFUSE. CONSENSUS OF GLOBAL MODELS SHOWS THE PRES GRADIENT REMAINING FAIRLY TIGHT INTO EARLY NEXT WEEK AS THE HIGH PRES SHIFTS SLOWLY EASTWARD TOWARD THE CAROLINAS...MAINTAINING MODERATE TO FRESH E FLOW OVER THE EASTERN GULF...AND SE RETURN FLOW OVER THE NW GULF. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... SHIP...BUOY AND ASCAT SCATTEROMETER DATA SHOW NE WINDS AROUND 15 TO 20 KT WINDS OVER THE FAR NW CARIBBEAN...AHEAD OF A COLD FRONT MOVING INTO THE SE GULF. WHILE THE FRONT WILL BECOME DIFFUSE BEFORE REACHING CARIBBEAN WATERS...HIGH PRES WILL BUILD N OF THE AREA BEHIND THE FRONT...ALLOWING MODERATE TO FRESH NE TO E FLOW OVER MUCH OF THE NORTHERN CARIBBEAN BY THE WEEKEND. FURTHER E OVER THE TROPICAL N ATLC WATERS E OF THE LESSER ANTILLES...A TROPICAL WAVE ALONG 51W IS COMING IN PHASE WITH AN UPPER CYCLONE NEAR 20N55W. A DEEP LAYER TROUGH REMAINS QUASI-STATIONARY ALONG ROUGHLY 55W BY 24 HOURS. GLOBAL MODEL CONSENSUS SHOWS THE DEVELOPMENT OF SURFACE LOW PRES ALONG THE TROUGH. THE GFS REMAINS THE MOST AGGRESSIVE MODEL...DEEPENING THE LOW TO A GALE CENTER BY SUN...MOST LIKELY DUE TO CONVECTIVE FEEDBACK ISSUES. STRONG CONVECTION IS ALREADY ONGOING IN THE DIVERGENT FLOW ALOFT...AND THIS FAVORS A DEVELOPING LOW PRES AREA. HOWEVER GIVEN THE STRONG SE SHEAR...THE LOW WILL NOT LIKELY DEEPEN TOO MUCH. FORECAST FAVORS MORE MODERATE BLEND OF ECMWF AND UKMET. THE MAIN IMPACT WILL BE A TIGHT GRADIENT BETWEEN THE SURFACE TROUGH AND HIGH PRES TO THE NW OVER THE CAROLINAS...MAINTAINING A LONG FETCH OF FRESH TO STRONG NE WINDS THROUGH EARLY NEXT WEEK THAT WILL EXTEND INTO THE NE CARIBBEAN. IN ADDITION...THIS WILL GENERATE SWELL WITH HEIGHTS TO 8 FT PUSHING THROUGH THE ATLANTIC PASSAGES INTO THE NE AND N CENTRAL CARIBBEAN STARTING SAT. SW N ATLC S OF 31N W OF 55W... A COLD FRONT EXTENDING FROM 31N71W TO S FLORIDA WILL WEAKEN AS IT PUSHES SE...REACHING FROM 31N64W TO THE STRAITS OF FLORIDA THROUGH LATE FRI. FRESH TO STRONG N FLOW BEHIND THE FRONT WILL VEER NE THROUGH TODAY AS HIGH PRES BUILDS EASTWARD BEHIND THE FRONT. WHILE THE FRONT ITSELF STALLS AND DISSIPATES BY SUN E OF THE AREA...FRESH TO STRONG NE FLOW WILL PERSIST BETWEEN DEVELOPING LOW PRES AND SURFACE TROUGHING ALONG 55W AND HIGH PRES N OF AREA EXTENDING FROM THE N CENTRAL ATLC THROUGH THE CAROLINAS. THE LONG DURATION AND FETCH WILL ALLOW SEAS TO BUILD TO AS HIGH AS 14 FT IN NE SWELL FROM LATE SUN INTO EARLY NEXT WEEK. 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 CHRISTENSEN