000 AGXX40 KNHC 221826 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 PM EST WED DEC 22 2010 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... ASIDE FROM A BACKDOOR-TYPE COLD FRONT THAT QUICKLY DROPS SE THROUGH THE EASTERN GULF TONIGHT AND THU...CONDITIONS WILL REMAIN RELATIVELY UNCHANGED OVER THE GULF THROUGH FRI WITH SE RETURN FLOW OVER THE WESTERN GULF AND HIGH PRES DOMINATING THE FLOW REGIME OVER THE EASTERN GULF. A STRONG COLD FRONT IS EXPECTED TO MOVE OFF THE TX/LA COAST BY EARLY SAT MORNING. THE 12Z GFS HAS COME INTO CONSIDERABLY BETTER AGREEMENT WITH THE MORE CONSISTENT ECMWF SOLUTION WITH THIS SYSTEM BY CARRYING A DISTINCT SURFACE LOW THROUGH THE NORTHERN GULF RATHER THAN THE MORE STRUNG OUT AND SLOWER SOLUTION IT HAD ON THE 06Z RUN. AS A RESULT...THE GFS HAS TRENDED CONSIDERABLY FASTER TO CARRY THE COLD FRONT EASTWARD THROUGH THE GULF AND NOW IS IN REASONABLE AGREEMENT WITH THE FRONTAL TIMING. THE ECMWF REMAINS STRONGER WITH THE SURFACE LOW THAN THE GFS. THE AFTERNOON FORECAST PACKAGE...WHICH WAS A BLEND OF THE GFS AND ECMWF...WILL NOW TREND TOWARD A FASTER AND DEEPER SOLUTION AS A RESULT OF THIS CHANGE IN THE GFS. BOTH MODELS KEEP WINDS JUST BELOW GALE FORCE WITH THE SYSTEM. CARIBBEAN AND TROPICAL N ATLC... THE PRES GRADIENT BETWEEN THE SOUTHWARD MOVING RIDGE AXIS OVER THE SW N ATLC AND LOWER PRES OVER SOUTH AMERICA IS GENERATING FRESH TO STRONG NE WINDS OVER THE NORTHERN HALF OF THE CARIBBEAN EASTERN CARIBBEAN INCLUDING THE WINDWARD PASSAGE TODAY AND THROUGH THU. WINDS ARE STRONGEST DOWNWIND OF THE MONA AND ANEGADA PASSAGES ACCORDING TO THE 1046 UTC WINDSAT AND 1430 UTC ASCAT PASSES WITH SEAS TO 9 FT WITHIN IN THE N SWELL PENETRATING THE N FACING PASSAGES OF THE NE CARIBBEAN. LATER IN THE FORECAST PERIOD...THE AFOREMENTIONED COLD FRONT IN THE GULF OF MEXICO SHOULD MOVE THROUGH THE YUCATAN CHANNEL SUN AND NW WINDS WILL INCREASE TO 20 KT ACROSS MUCH OF THE WESTERN GULF BY SUN NIGHT. AS MENTIONED IN THE GULF OF MEXICO SECTION...THE 12Z GFS HAS NOW COME INTO CONSIDERABLY BETTER AGREEMENT WITH THE 00Z ECMWF WITH THIS FRONT AND THE AFTERNOON FORECAST WILL REFLECT THIS SOLUTION. SW N ATLC... THE ASCAT PASS FROM 1426 UTC SHOWED WINDS TO GALE FORCE HAVE SHIFTED E OF THIS FORECAST ZONE...BUT NW WINDS TO 25 KT STILL CAN BE FOUND OVER THE NE CORNER. NW SWELLS ARE STILL UPWARDS OF 20 FT IN THIS AREA...WITH BUOY 41049 REPORTING 23 FT SEAS AT 1700 UTC JUST E OF THE AREA NEAR 27.5N63W. HIGH PRES DOMINATES THE S PART OF THE FORECAST ZONE...KEEPING WINDS LIGHT. A COLD FRONT WILL MOVE INTO N WATERS TONIGHT AND QUICKLY PUSH SE OF THE AREA BY SUNSET FRI...WITH WINDS JUST BELOW GALE FORCE EXPECTED. THE MODELS REMAIN IN REASONABLE AGREEMENT ON THIS SCENARIO. THE 12Z GFS HAS COME INTO MUCH BETTER AGREEMENT WITH THE HPC PREFERRED ECMWF SOLUTION WITH THE STRONG COLD FRONT NOW EXPECTED TO MOVE INTO NW WATERS EARLY SUN. AS EXPLAINED IN THE GULF OF MEXICO SECTION...THE 12Z GFS HAS COME INTO CONSIDERABLY BETTER AGREEMENT WITH THE MORE CONSISTENT ECMWF SOLUTION WITH THIS SYSTEM BY CARRYING A DISTINCT SURFACE LOW THROUGH THE NORTHERN GULF AND INTO THE SW N ATLC RATHER THAN THE MORE STRUNG OUT COASTAL LOW DEVELOPMENT AND SLOWER SOLUTION WITH THE COLD FRONT IT HAD ON THE 06Z RUN. A MENTION OF GALE FORCE WINDS NEAR THE FRONT WAS ADDED TO THE MORNING FORECAST PACKAGE AND THE 12Z UKMET...GFS...AND 00Z ECMWF ALL HAVE WINDS TO 40 KT AHEAD OF THE FRONT AND TO 35 KT BEHIND THE FRONT BY MID DAY SUN. WARNINGS.. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER