000 AGXX40 KNHC 251818 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 120 PM EST SAT DEC 25 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... AN AREA OF LOW PRES IS SKIRTING THROUGH THE NORTHERN GULF COASTAL PLAIN AND WILL QUICKLY MOVE NE OF THE AREA TONIGHT. SEVERAL BUOYS IN THE NORTH CENTRAL GULF AHEAD OF THE LOW ARE REPORTING SW WINDS IN THE 20-25 KT RANGE AND THE 1506 UTC ASCAT PASS AGREES. THE NEXT OFFSHORES ISSUANCE WILL UPDATE FOR STRONGER WINDS HERE AHEAD OF THE LOW. THE LATEST GFS AND ECMWF ARE IN REASONABLE AGREEMENT ON THE TIMING OF THIS FRONT AND THE TIMING OF THE WINDS DIMINISHING BEHIND IT. BOTH MODELS KEEP WINDS JUST BELOW GALE FORCE WITH THE SYSTEM. RELIED PRIMARILY ON THE MWW3 FOR WAVE HEIGHT GUIDANCE BUT ATTEMPTED TO CORRECT FOR THE BIAS IN THE MWW3 TO HOLD ONTO HIGHER SEAS TOO LONG AFTER THE WINDS HAVE DIMINISHED. THE 12Z GFS AND 00Z ECMWF AGREE ON BRINGING THE SE RETURN FLOW IN THE GULF TO 20 KT OVERNIGHT MON NIGHT...BUT THESE MODELS DIVERGE BY TUE WHEN THE GFS BECOMES STRONGER WITH THE WINDS NEARSHORE IN THE NW GULF BECAUSE IT IS FASTER TO CARRY A SOUTHERN STREAM TROUGH EASTWARD THROUGH MEXICO AND THE ECMWF. THE UKMET IS IN BETTER AGREEMENT WITH THE SLOWER ECMWF. PAST EXPERIENCE SHOWS THAT THE UKMET IS GENERALLY GOOD AT HANDLING SUCH A PATTERN AND IT TYPICALLY PREFERS A SLOWER SOUTHERN STREAM SOLUTION IS MUCH A CASE. THEREFORE...LEANED TOWARD THE ECMWF FOR THE FORECAST PAST MON NIGHT. CARIBBEAN AND TROPICAL N ATLC... SURFACE OBSERVATIONS AND THE 1328 AND 1508 UTC ASCAT PASSES SHOW WIDESPREAD FRESH NE WINDS IN THE EASTERN AND CENTRAL CARIBBEAN THIS AFTERNOON WITH STRONG NE WINDS PRIMARILY NEAR THE COAST OF COLOMBIA. IN ADDITION...N SWELL BEHIND THE ATLC COLD FRONT HAS BEGUN TO MOVE THROUGH THE N FACING ATLC PASSAGES INTO THE EASTERN CARIBBEAN. THE AFOREMENTIONED COLD FRONT IN THE GULF OF MEXICO SHOULD MOVE THROUGH THE YUCATAN CHANNEL SUN AND N WINDS TO 25 KT ARE EXPECTED TO RAPIDLY FILTER S THROUGH THE WESTERN CARIBBEAN WHILE WINDS DIMINISH OVER THE EASTERN AND CENTRAL CARIBBEAN. THE 00Z ECMWF AND 12Z GFS CONTINUE TO BE IN GOOD AGREEMENT HERE. THE LEADING EDGE OF THE COLD FRONT TRAVELS THROUGH THE WINDWARD PASSAGE MON AND THE MONA AND ANEGADA PASSAGES TUE. WINDS WILL LIKELY BE INTENSIFIED AS THEY FUNNEL THROUGH THE PASSAGES...WITH THE GFS AND ECMWF SHOWING WINDS TO JUST BELOW GALE FORCE IN THE MONA PASSAGE AND OFF THE SE COAST OF THE DOMINICAN REPUBLIC BY SUNSET TUE AND OVERNIGHT TUE NIGHT. SW N ATLC... CONDITIONS ARE RELATIVELY QUIET OVER THE SW N ATLC AT THE MOMENT...BUT A STRONG COLD FRONT WILL MOVE INTO NW WATERS BEFORE SUNRISE SUN. THE MODELS HAVE COME INTO REASONABLY GOOD AGREEMENT WITH THE TIMING OF THE FRONT AND THE EXPANSE OF THE GALE FORCE WIND FIELD ASSOCIATED WITH IT. BOTH THE 12Z GFS AND A SNEAK PEAK AT THE NEW 12Z ECMWF ARE SHOWING WINDS BRIEFLY REACHING 40 KT AHEAD OF THE FRONT SUN MORNING. GALE FORCE WINDS ARE FORECAST WITHIN 210 NM ON EITHER SIDE OF THE FRONT SUN THROUGH MON MORNING. HOWEVER...BOTH MODELS NOW MAINTAIN GALE FORCE WINDS OVER THE ZONE THROUGH 0600Z TUE. ALOFT...BOTH MODELS CARRY STRONG SHORTWAVE ENERGY INTO THE BACKSIDE OF THE TROUGH THAT HELPS SPUR ON THESE STRONG WINDS. THE FORECAST MAY BE REVISED THIS AFTERNOON TO REFLECT A LONGER GALE PERIOD. WARNINGS.. ATLC... .GALE WARNING N OF 27N WITHIN 210 NM OF FRONT SUN THROUGH EARLY MON...AMZ080. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER