000 AGXX40 KNHC 031957 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 300 PM EST SAT DEC 03 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... THE PRELIMINARY 18 UTC SURFACE ANALYSIS SHOWS A HIGH PRES RIDGE EXTENDING FROM SE U.S. SW TO OVER THE THE MIDDLE GULF. THE SUPPORTING UPPER LEVEL HIGH EXETNDS FROM A CREST OVER THE CAROLINAS SW TO THE SW GULF ZONE. TO THE W OF THE SURFACE RIDGE 20-25 KT SUSTAINED SE-S WINDS ARE NOTED IN THE BUOY OBSERVATIONS. THE ASSOCIATED SEAS ARE IN THE RANGE OF 7-10 FT WITH THE HIGHEST FROM 25N TO 28N W OF 94W. THE RESPONSIBLE TIGHT GRADIENT IS DUE TO THE PRES DIFFERENCE BETWEEN A DEEP UPPER LEVEL LOW PRES SYSTEM OVER THE SW U.S. AND NW MEXICO...AND THE SURFACE RIDGE. BUOY REPORTS OVER THE REMAINDER OF THE GULF SHOW E-SE WINDS OF 15-20 KT WITH THE EXCEPTION OF THE FAR SRN WATERS S OF ABOUT 25N E OF 90W WHERE A TIGHTER PRES GRADIENT IS SUPPORTING E 20-25 KT WINDS. SEAS ELSEWHERE ARE IN THE 5-8 FT RANGE WITH MUCH HIGHER SEAS OF 8-10 FT IN THE FAR SE WATERS. THE FORECAST IS ON TRACK TO FOR THE RIDGE TO SHIFT EASTWARD TO THE FAR NE GULF BY MON EVENING AS A COLD FRONT ASSOCIATED WITH THE UPPER LEVEL LOW PRES SYSTEM MOVES TO EASTERN TEXAS ON SUN. SE TO S WINDS ARE EXPECTED TO INCREASE TO 20-25 KT OVER THE NW GULF WATERS N OF 25N ON SAT BEFORE DIMINISHING SOME TO 15-20 KT ON SUN. THE COLD FRONT WILL MOVE THROUGH EASTERN TEXAS THROUGH SUN EVENING BEFORE MOVING OFF THAT COAST EARLY ON MON AS INDICATED BY LATEST MODEL RUNS. THE FRONT WILL QUICKLY REACH FROM SOUTHERN LOUISIANA TO NEAR TAMPICO MEXICO MON...THEN EXTEND FROM THE FLORIDA PANHANDLE TO BAY OF CAMPECHE BY TUE EVENING. THE FRONT WILL BEGIN TO WEAKEN AS IT EXITS THE GULF LATE ON WED. STRONG OFFSHORE WILL DEVELOP BEHIND THE FRONT OVER THE MUCH OF AREA. POSSIBLE BRIEF GALE FORCE WINDS ARE EXPECTED BEHIND THE FRONT IN THE SW GULF TUE AND WED WITH NW-N WINDS OF 20-30 KT ELSEWHERE OVER THE WESTERN GULF. SEAS ARE EXPECTED TO BUILD TO 8-11 FT BEHIND THE FRONT WITH HIGHER SEAS OF 10-15 FT IN THE SW GULF PORTION ON TUE AND WED PRIMARILY W OF 95W...AND UP TO 13 FT E OF 95W IN THAT SAME ZONE. SEAS ELSEWHERE BUILD TO 8 FT THROUGH TUE...BUT THEN SUBSIDE ALL LOCATIONS WED AND THU AS WEAKENING HIGH PRES SETTLES IN ACROSS THE GULF. CARIBBEAN SEA AND TROPICAL N ATLC... LATEST SATELLITE IMAGERY SHOWS EXTENSIVE OVERCAST CLOUDINESS WITH EMBEDDED SCATTERED SHOWERS AND TSTMS CONFINED TO THE SE SECTION OF THE CARIBBEAN...AND WESTERN PORTION OF THE TROPICAL N ATLC IN ASSOCIATION WITH A PERSISTENT TROUGH THAT EXTENDS FROM ROUGHLY FROM LEEWARD ISLANDS SW TO ABC ISLANDS. THE TROUGH IS TO THE E OF A BROAD UPPER TROUGH THAT HAS MOVED INTO THE EASTERN CARIBBEAN. BOTH BUOY OBSERVATIONS...AND MINIMAL ASCAT DATA FROM THIS MORNING REVEAL NE 15-20 KT WINDS OVER MUCH OF THE OF THE WESTERN AND MIDDLE PORTIONS OF THE CARIBBEAN AS WELL AS TO THE W AND NW OF THE TROUGH WITH LIGHTER E WINDS OF 10-15 KT TO THE E OF THE TROUGH. WINDS WILL BE HIGHER IN THE SHOWER AND TSTM ACTIVITY OVER THE NEXT FEW DAYS AS THE TROUGH ONLY MOVES LITTLE. ATLC HIGH PRES WILL BUILD EASTWARD AND STRENGTHEN THROUGH SUN ...THEN WEAKEN MON THROUGH THU AS COLD FRONT ENTERS THE NW CARIBBEAN WED NIGHT AND WEAKENS THERE INTO THU. N-NE WINDS OF 10-15 KT WILL INITIALLY FOLLOW IN BEHIND THE FRONT...BUT THEN INCREASE TO 15-20 KT THROUGH THU AS GULF OF MEXICO HIGH PRES SHIFTS EASTWARD. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... THE PRELIMINARY 18 UTC SURFACE ANALYSIS SHOWS A DISSIPATING TROUGH EXTENDING FROM NEAR 31N58W TO THE LEEWARD ISLANDS WHERE IT CONNECTS TO THE CARIBBEAN TROUGH. BUOY OBSERVATIONS AND ASCAT DATA SUPPORT NE WINDS OF 20-25 KT W OF THE TROUGH. LIGHTER N-NE WINDS OF 10 KT ARE E OF THE TROUGH. THE TROUGH WILL BE A NON-FEATURE ON SUN AS VERY LARGE AREA OF HIGH PRES BUILDS EASTWARD WHILE STRENGTHENING ACROSS MUCH OF THE WATERS THROUGH THE WEEKEND. THIS LARGE HIGH PRES AREA WILL BE THE MAIN FEATURE OF IMPACT TO THE AREA WITH RESPECT TO WINDS AND SEAS INTO EARLY NEXT WEEK. THE HIGH IS FORECAST BY THE MODELS TO WEAKEN MON THROUGH THU AS THE ABOVE DESCRIBED GULF OF MEXICO COLD FRONT EMERGES OFF THE SE U.S. AND NE FLORIDA COASTS WED NIGHT AND FURTHER INTO THE FAR NW WATERS THU. BEFORE THEN...THE TIGHT PRES GRADIENT INDUCED BY THE STRONG HIGH WILL BRING NE WINDS OF 20-30 KT OVER MUCH OF THE AREA THROUGH LATE SUN NIGHT BEFORE DIMINISHING TO AROUND 15-20 KT MON AND TUE...AND TO E AT 10-15 KT OVER MUCH OF THE AREA BY THU...WITH THE EXCEPTION OF S OF 25N E OF THE BAHAMAS WHERE E WINDS OF 15-20 KT SHOULD BE EVIDENT. WINDS BECOME S-SW 15-20 KT OVER THE FAR NW WATERS WED AHEAD OF THE FRONT AND NW 20-25 KT NW OF THE FRONT. WARNINGS... GULF OF MEXICO... .GMZ082...GALE CONDITIONS EXPECTED TUE S OF 22N W OF 95W... .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE