000 AGXX40 KNHC 170925 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 240 PM EST SUN DEC 16 2012 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... ATLC RIDGE MAINTAINS GENTLE BREEZE OVER GULF WATERS AS WEAK COLD FRONT ENTERS NW CORNER. SW WINDS BECOME MODERATE TO FRESH BREEZE N OF 28N WITHIN 120 NM E OF FRONTAL BOUNDARY. FRONT REACH FROM STRAITS OF FLORIDA TO NE YUCATAN PENINSULA LATE TUE AND BROAD ANTICYCLONIC GENTLE BREEZE SETS UP ACROSS ENTIRE BASIN TUE NIGHT...EXCEPT N OF 24N W OF 95W WED WHERE SLY RETURN FLOW BECOMES A MODERATE BREEZE IN ANTICIPATION OF NEW AND MUCH STRONGER COLD FRONT. SECOND COLD FRONT ENTERS NW GULF ZONES LATE WED NIGHT WITH FRESH TO STRONG SW WINDS WITHIN 150 NM E OF BOUNDARY AND STRONG TO NEAR GALE FORCE N WINDS W OF FRONT. IT QUICKLY REACHES FROM BIG BEND FLORIDA TO 18N94W IN BAY OF CAMPECHE LATE THU AND EXITS GULF EARLY FRI. IN ITS WAKE IT LEAVES AN ALMOST ENTIRE GULF BASIN IN STRONG TO NEAR GALE FORCE NE WINDS...EXCEPT W OF 96W. GFS SOLUTION INCLUDES GALE FORCE WINDS BUT ECMWF AND UKMET AS WELL AS THE CONSENSUS STOP SHY OF GALES. FORECAST FOLLOWS GFS POSITIONS BUT HOLDS SHORT ON THE GALES. SEAS EXPECTED TO REACH 12-13 FT IN BAY OF CAMPECHE W OF 93W AND 8-11 ELSEWHERE UNDER STRONG NE WINDS. SW N ATLC S OF 31N W OF 65W... WESTERN SIDE OF BROAD HIGH PRES RIDGE COVERS ENTIRE BASIN WITH GENTLE TO MODERATE E-SE BREEZE THROUGHOUT...EXCEPT SOUTHERLY AND INCREASING RETURN FLOW ALONG FLORIDA E COAST. WEAK COLD FRONT ENTERS NW CORNER LATE MON CHANGING RETURN FLOW FROM A FRESH S BREEZE TO A STRONG NW WIND N OF 28N WITH SEAS 10-12 FT. FRONT QUICKLY MOVES E OF REGION WITH 1022 MB HIGH PRES CENTER BUILDING UP OVER AREA THU MODERATING WIND AND SEAS FOR A SHORT WHILE. CONDITIONS DETERIORATE QUICKLY FRI AS STRONG RETURN FLOW SETS UP ALONG E COAST OF FLORIDA WITH APPROACH OF MUCH STRONGER COLD FRONT. STRONG TO NEAR GALE SW FLOW AHEAD OF FRONT QUICKLY TURN NW LATE THU AS FRONT ENTERS NW CORNER OF BASIN AND BRING BLAST OF MUCH COLDER AIR MASS...NEAR GALE WINDS AND SEAS OVER 12 FT INTO SW N ATLC. SUSTAINED GALE FORCE WINDS ARE EXPECTED JUST N OF 31N...BUT MODEL GUIDANCE AGREE IN HOLDING SHY S OF 31N. SEAS BUILD TO 15-17 FT N OF 31N BUT N 10 FT SWELLS INTRUDE INTO SW N ATLC AND SPREAD S TO GREATER ANTILLES E OF BAHAMAS THROUGH REST OF FORECAST PERIOD. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... FLAT PRES GRADIENT CONTINUES AS WEAK ATLC HIGH PRES IS FORCED E BY INCOMING COLD FRONT MAINTAINING MODERATE E BREEZE ACROSS ENTIRE CARIBBEAN. PATTERN HOLDS THROUGH LATE WED WHEN NEW RIDGE BUILDS OVER SW N ATLC AND TIGHTENS GRADIENT AGAIN. ELY WINDS ACROSS CENTRAL CARIBBEAN FROM 70W-80W INCREASE BUILDING SEAS TO 10 FT ALONG COAST OF COLOMBIA. SOME N FROM SW N ATLC SWELLS REACH NORTHERN LATITUDES OF TROPICAL ATLC ZONE AND SEEP THROUGH WINDWARD...MONA AND ANEGADA PASSAGES INTO CARIBBEAN SEA LATE IN FORECAST PERIOD. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER WALLY BARNES