000 AGXX40 KNHC 011946 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 PM EST THU DEC 01 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 ACROSS THE MIDDLE AND SW GULF PORTIONS. WATER VAPOR IMAGERY SUGGESTS THAT THE HIGH PRES IS ALSO IN THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE OVER THOSE AREA. TO THE W OF THE RIDGE SELY RETURN FLOW IS ALREADY UNDER WAY AHEAD OF THE NEXT FRONTAL SYSTEM AS INDICATED BY BUOY OBSERVATIONS FROM THE WESTERN GULF OF MEXICO. E OF THE RIDGE NE-E MODERATE TO FRESH WINDS ARE PRESENT AS SEEN IN THE BUOY REPORTS...AND AS CONFIRMED BY AN ASCAT PASS FROM NEAR 16 UTC THIS MORNING. THE FORECAST CALLS FOR THE RIDGE TO SHIFT EASTWARD OVER THE NEXT 2 TO 3 DAYS AS THE FRONTAL SYSTEM MAKES HEADWAY ACROSS TEXAS... AND APPROACHES THAT COAST ON SUN. SE TO S WINDS ARE EXPECTED TO INCREASE TO 20-25 KT OVER THE NW GULF WATERS FROM 25N-28N W OF 94W BEGINNING LATE TONIGHT INTO SAT NIGHT WHILE WINDS ELSEWHERE WILL BE E-SE IN THE 20-25 KT RANGE. THE COLD FRONT WILL MOVE THROUGH EASTERN TEXAS DURING THE DAY ON SUN BEFORE MOVING OFF THAT COAST ON SUN EVENING. LATEST MODEL RUNS ARE PRETTY GOOD AGREEMENT ON TIMING OF COLD FRONT PASSAGE OFF THE TEXAS INTO THE FAR WESTERN TO OCCUR ON SUN EVENING. THIS IS SLOWER THAN PREVIOUSLY FORECASTED. FOR COLD FRONT POSITIONS...WILL TAKE THE FRONT TO ALONG A LINE FROM FROM SOUTHERN LOUISIANA TO NEAR TAMPICO MEXICO MON...AND FROM THE FAR WESTERN FLORIDA PANHANDLE TO 25N92W TO EASTERN BAY OF CAMPECHE BY LATE TUE AFTERNOON. STRONG OFFSHORE FLOW WILL FOLLOW IN BEHIND THE FRONT WITH NW-N WINDS OF 20-30 KT WITH THE HIGHEST OF THE WIND RANGE LIKELY EXPECTED S OF 26N. WILL HOLD OFF FOR NOW ON POSTING GALE CONDITIONS BEHIND THE FRONT AS FORECAST MODEL WINDS APPEAR TO BE LOWER THAN GALE FORCE THRESHOLD IN ADDITION TO ENSEMBLE GALE PROBABILITIES ALSO BEING VERY MINIMAL. EXPECT SEAS TO BUILD UP TO 8-11 FT ON MON...AND TO 9-14 FT TUE IN THE SW GULF USING A COMBINATION OF THE CONVENTIONAL AND ECMWF WAVEWATCH GUIDANCE. CARIBBEAN SEA AND TROPICAL N ATLC... A DISSIPATING FRONTAL TROUGH EXTENDS FROM EASTERN CUBA SW TO SOUTHERN COSTA RICA EARLY THIS AFTERNOON. BOTH BUOY OBSERVATIONS ...AND A PARTIAL ASCAT PASS FROM THIS MORNING REVEAL PERSISTENT N-NE 15-20 KT WIND FLOW BEHIND THE TROUGH...WHILE LIGHTER NE-E 10-15 KT WINDS ARE ELSEWHERE ACROSS THE CARIBBEAN AND TROPICAL N ATLC...WITH THE EXCEPTION OF N OF 16N E OF 60W WHERE SE-S 15-20 KT WINDS ARE NOTED. ANOTHER TROUGH IS ALONG 61W S OF ABOUT 16N DRIFTING W. SATELLITE IMAGERY FROM THROUGHOUT THE DAY HAS SHOWN A VERY WELL DEFINED INVERTED-V SHAPE CLOUD PATTERN WITH THE TROUGH. THE TROUGH IS JUST TO THE E OF A NARROW UPPER TROUGH OVER THE EASTERN PORTION OF THE CARIBBEAN. WITH THE UPPER TROUGH EXPECTED TO REMAIN NEARLY STATIONARY OVER THE NEXT FEW DAYS...THE SURFACE TROUGH WILL ONLY MOVE SLIGHTLY WESTWARD THROUGH SUN. SCATTERED TO NUMEROUS SHOWERS AND TSTMS ASSOCIATED WITH THE TROUGH WILL CONTINUE TO IMPACT THE FAR SE CARIBBEAN SEA AND MOST OF THE TROPICAL N ATLC THROUGH AT LEAST SUN. ATLC HIGH PRES WILL BUILD EASTWARD AND STRENGTHEN THROUGH SAT...THEN WEAKEN SUN THROUGH TUE ALLOWING FOR NE-E WINDS OF 10-15 KT TO EXIST OVER JUST ABOUT THE ENTIRE AREA BY TUE. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... THE PRELIMINARY 18 UTC SURFACE ANALYSIS SHOWS A DISSIPATING STATIONARY FRONT EXTENDING FROM 31N68W TO A WEAK LOW TO MID LEVEL CYCLONIC SWIRL AT 23N74W AND TO EASTERN CUBA. BUOY OBSERVATIONS AND RECENT ASCAT DATA SHOWED AND ARE CURRENTLY SHOWING N-NE WINDS OF 10-15 KT BEHIND THE FRONT. LIGHTER N WINDS OF 10 KT ARE E OF THE FRONT N OF ABOUT 24N...AND N-NE 5-10 KT S OF 24N. THE FRONT WILL DISSIPATE EARLY FRI AS A VERY LARGE AREA OF HIGH PRES BUILDS IN BEHIND IT OVER THE WESTERN WATERS. 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 BUILD EASTWARD AND STRENGTHEN THROUGH SUN...THEN WEAKEN MON AND TUE. THE RESULTANT TIGHT PRES GRADIENT WILL BRING NE WINDS OF 20-30 KT OVER MUCH OF THE AREA BEGINNING ON FRI...AND LASTING INTO MON AFTERNOON BEFORE DIMINISHING TO AROUND 15-20 KT. ALONG WITH THE WINDS...SEAS WILL BUILD TO 13 FT NE AND E OF THE BAHAMAS OVER THE UPCOMING WEEKEND...THEN DIMINISH TO AROUND 10 FT LATE MON INTO TUE AS THE HIGH SLIDES EASTWARD AND WEAKENS IN RESPONSE TO FRONTAL SYSTEM THAT SWEEPS ACROSS THE GULF OF MEXICO. WARNINGS... GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE