000 AGXX40 KNHC 231818 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 120 PM EST THU DEC 23 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... A COLD FRONT IS BISECTING THE GULF NEAR 27N WITH SURFACE OBSERVATIONS SHOWING WINDS ARE GENERALLY N TO NE AT 15 KT N OF THE BOUNDARY. THE WESTERN PORTION OF THIS FRONT WILL DISSIPATE TONIGHT WHILE THE EASTERN PORTION PUSHES E OF THE AREA WITH LITTLE FANFARE. A STRONG COLD FRONT IS EXPECTED TO MOVE OFF THE TX/LA COAST BY EARLY SAT MORNING. THE 12Z GFS IS WEAKER AND FASTER WITH THE LOW PRES SYSTEM THAN THE MORE CONSISTENT ECMWF SOLUTION AND THE GFS CARRIES A MORE POSITIVELY TILTED TROUGH ALOFT WHICH DELAYS THE SOUTHERN END OF THE COLD FRONT MOVING SE TOWARD THE YUCATAN CHANNEL. BOTH MODELS KEEP WINDS JUST BELOW GALE FORCE WITH THE SYSTEM. CARIBBEAN AND TROPICAL N ATLC... THE PRES GRADIENT BETWEEN THE WEAKENED RIDGE AXIS OVER THE SOUTHERN BAHAMAS AND LOWER PRES OVER SOUTH AMERICA HAS SLACKENED SOME COMPARED TO THIS TIME YESTERDAY. WINDS TO 20 KT ARE CONFINED PRIMARILY TO S OF JAMAICA BUT SEAS TO 8 FT ARE MORE WIDESPREAD IN THE CENTRAL CARIBBEAN DUE TO SWELL PENETRATING THROUGH THE MONA AND ANEGADA PASSAGES FROM THE ATLC. LATER IN THE FORECAST PERIOD...THE AFOREMENTIONED COLD FRONT IN THE GULF OF MEXICO SHOULD MOVE THROUGH THE YUCATAN CHANNEL. THE MANUAL PROGS WERE ADJUSTED TO THE 00Z ECMWF WHICH CARRIES THE COLD FRONT SOUTHWARD INTO THE YUCATAN CHANNEL FASTER ON SUN MORNING THAN THE GFS. NW WINDS WILL INCREASE TO 20 KT ACROSS MUCH OF THE WESTERN GULF BY SUN NIGHT AND CONTINUE INTO MON. SW N ATLC... AT 1200 UTC...A COLD FRONT WAS FROM THE NE CORNER OF THE ZONE TO SEBASTIAN INLET. THE ASCAT PASS FROM 1406 UTC SHOWED WINDS TO 30 KT BEHIND THE COLD FRONT OVER NE WATERS. THIS COLD FRONT WILL QUICKLY PASS SOUTH...MOVING SE OF THE ZONE BY FRI AFTERNOON. A STRONGER COLD FRONT WILL MOVE INTO NW WATERS EARLY SUN. THE GFS IS FASTER AND WEAKER WITH THE LOW PRES SYSTEM THAT PASSES THROUGH FAR NW WATERS LEADING THE COLD FRONT AND...AS EXPLAINED IN THE GULF OF MEXICO SECTION...THE 12Z GFS CARRIES A MORE POSITIVELY TILTED TROUGH ALOFT WHICH LEADS TO A SLOWER PROGRESSION OF THE SOUTHERN EDGE OF THE COLD FRONT THROUGH THE STRAITS OF FLORIDA SUN AFTERNOON COMPARED TO THE 00Z ECMWF. GALE FORCE WINDS ARE FORECAST WITHIN 210 NM ON EITHER SIDE OF THE FRONT SUN THROUGH MON MORNING. WHILE THE GFS AND ECMWF HAVE TIMING DIFFERENCES...THEY AGREE ON THE DEVELOPMENT OF GALE FORCE WINDS. BY LATE MON...THE MORE AMPLIFIED ECMWF SOLUTION MAINTAINS 30 KT WINDS OVER NW WATERS...STRONGER THAN THE GFS. FOR NOW...A COMPROMISE SOLUTION WAS USED FOR THE FORECAST. WARNINGS.. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER