000 AGXX40 KNHC 181948 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 PM EST SUN DEC 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... METEOROLOGICAL DATA FROM BOTH BUOYS AND OIL RIG PLATFORMS ALONG WITH PARTIAL ASCAT DATA FROM THIS MORNING REVEAL NE-E WINDS OF 15-20 KT THROUGHOUT EXCEPT IN THE FAR WESTERN PORTION WHERE WINDS HAVE ALREADY VEERED TO THE E-SE IN DIRECTION. SATELLITE IMAGERY AND NWS RADAR DISPLAYS SHOW AREAS OF DENSE LOW AND MID LEVEL CLOUDS WITH EMBEDDED AREAS OF RAIN HUGGING THE FAR WESTERN BOUNDARY OF THE GULF FROM 21N TO 26N AND W OF 96W. THE CLOUDS ARE DISPERSING TO THE NW IN THE E-SE FLOW. SEAS ARE IN THE RANGE OF 3-5 FT THROUGHOUT...EXCEPT 5-6 FT FAR SE PART NEAR STRAITS OF FLORIDA AND 2-4 FT N OF ABOUT 28N. SURFACE ANALYSIS FROM THROUGHOUT THE DAY HAVE DEPICTED A LARGE AREA OF HIGH PRES CENTERED OVER THE SOUTHEASTERN U.S. WITH RIDGING BUILDING SEWD ACROSS THE GULF. THE FORECAST STILL HOLDS FOR THE HIGH TO SLIDE EASTWARD TO OFFSHORE THE SE U.S. ON MON ALLOWING FOR SOUTHERLY RETURN FLOW TO SET UP THE ENTIRE AREA...AND WHILE LOW PRES DEEPENS OVER WESTERN TEXAS TRACKS NE. BY LATE MON SLY RETURN FLOW AT 15-20 KT WILL COVER THE ENTIRE GULF. THE NEXT COLD FRONT IS FORECAST BY THE MODELS TO EMERGE OFF THE TX COAST EARLY TUE...AND MOVE E TO A POSITION FROM MISSISSIPPI DELTA TO THE CENTRAL BAY OF CAMPECHE TUE NIGHT. THE FRONT IS FORECAST TO BECOME QUASI-STATIONARY FROM THE WESTERN FLORIDA PANHANDLE TO EASTERN BAY OF CAMPECHE LATE WED THROUGH FRI. THE MODELS...WITH THE EXCEPTION OF THE GFS...TEND TO BE FASTER WITH MOVEMENT OF THE FRONT FOR DAYS 4 AND 5. WILL LEAN TOWARDS THE SLOWER GFS FOR THIS FORECAST FOR FRONTAL PSN AT DAYS 4 AND 5...AND MAINTAIN IT QUASI-STATIONARY AS THE UPPER LEVEL PROGS DON'T SHOW ANY GOOD PUSH ALOFT FOR THE FRONT TO PROCEED EASTWARD DURING THE LONG TERM OF THE FORECAST PERIOD. EXPECT WINDS TO BECOME N-NE 15-20 KT BEHIND THE FRONT AFTER TUE NIGHT. SOUTHWEST N ATLC S OF 31N W OF 65W... THE PRELIMINARY 18 UTC SURFACE MAP HAS A COLD FRONT EXTENDING FROM 31N67W SW TO THE CENTRAL BAHAMAS WHERE IT WEAKENS. A HIGH PRES RIDGE IS BUILDING SEWD ACROSS THE WESTERN ATLC BEHIND THE FRONT. A STRONG PRES GRADIENT OVER MUCH OF THE WATERS N OF 29N IS ALLOWING FOR GALE FORCE WINDS TO MANIFEST BEHIND THE FRONT TO 72W...AND E OF THE FRONT AS WELL. LARGE SEAS OF 10-15 FT ARE BUILDING WITHIN THE AREA OF GALE FORCE WINDS. ELSEWHERE S OF THE FRONT W OF 74W WINDS ARE NE AT 20 KT...WITH SEAS OF 5-7 FT. E OF THE BAHAMAS SEAS UP TO 9 FT IN N SWELLS ARE BEING REPORTED BY BUOYS 41046 AT 24N68W AND 41043 AT 21N65W. THE FRONT WILL REACH FROM NEAR BERMUDA TO THE SE BAHAMAS AT SUNRISE MON...FROM 31N62W TO THE CENTRAL BAHAMAS AT SUNSET MON...AND WEAKEN TO A SHEAR AXIS ALONG 21N LATE TUE. STRONG NLY WINDS BEHIND THE FRONT WILL DIMINISH OVER THE NW WATERS MON...WITH SLY RETURN FLOW SPREADING E ACROSS THE NORTHERN WATERS TUE...AND INCREASING OFF THE NE FL COAST WED IN ADVANCE OF ANOTHER WEAK FRONT FORECAST TO PUSH OFF THE SE U.S. COAST LATE THU AND WEAKEN INTO FRI. CARIBBEAN SEA AND TROPICAL N ATLC... THE BROAD SCALE PATTERN DOMINATED BY STRONG ATLC HIGH PRES WILL SUPPORT A FAIRLY TIGHT PRES GRADIENT THROUGHOUT MAINTAINING NE WINDS OF 20-25 KT ACROSS MUCH OF THE AREA. NE-E WINDS OF 20-30 KT ARE EXPECTED IN THE SW CARIBBEAN WED AND THU...AND TO ALONG THE COAST OF COLOMBIA FRI. SEAS THERE ARE EXPECTED TO BUILD UP TO 14 FT. ANOTHER MAIN ISSUE TO CONTINUE TO IMPACT THE TROPICAL N ATLC WATERS AND ATLC PASSAGES IN THE NE CARIBBEAN SEA WILL BE LARGE N SWELLS UP TO 10 FT THROUGH MON NIGHT. ANOTHER BATCH OF LARGE N SWELLS WILL BE BEGIN TO MOVE INTO THE TROPICAL N ATLC AND NE CARIBBEAN TUE THROUGH FRI WITH SEAS BUILDING UP TO 14 FT WED AND THU...AND GRADUALLY SUBSIDE TO AROUND 11 FT ON FRI. WARNINGS... GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .AMZ080...GALE WARNING N OF 29N E OF 72W... FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE