000 AGXX40 KNHC 011835 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 PM EDT MON OCT 01 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... CURRENT SATELLITE IMAGERY SHOW THE COLD FRONT THAT MOVED INTO THE AREA ON SUN HAS NOW REACHED FROM NEAR PENSACOLA FLORIDA SW TO 25N89W TO VERACRUZ MEXICO. SCATTERED SHOWERS AND A FEW TSTMS WITH GUSTY WINDS MARK A SQUALL LINE AHEAD OF THE FRONT WITHIN 60 NM OF LINE FROM 27N87W TO 30N86W...AND WITHIN 30 NM OF LINE FROM 23N90W T0 27N87W. CURRENT AND LATEST BUOY AND OIL PLATFORM OBSERVATIONS SHOW S-SW WINDS OF 20-25 KT AHEAD OF THE FRONT TO 86W AND N OF 26N...AND ALSO BEHIND THE FRONT TO 94W AND N OF 26N. THE OBSERVATIONS ALSO SHOW SEAS OF UP TO 9 FT BEHIND THE FRONT AND E OF FRONT TO NEAR 86W. WEAK HIGH PRES IS BUILDING ACROSS THE GULF BEHIND THE FRONT. OBSERVED SEA STATE MATCHES THE NOAA WAVEWATCH III MODEL GUIDANCE PRETTY WELL INCLUDING PICKING UP THE MAX SEAS BEHIND THE FRONT. MODELS ARE IN GOOD AGREEMENT THAT THE FRONT WILL REACH A POSITION FROM THE WESTERN FLORIDA PANHANDLE TO NEAR 25N88W TO THE NORTHERN YUCATAN PENINSULA TONIGHT...THEN BEGIN TO WEAKEN AS IT IT REACHES FROM THE BIG BEND REGION OF FLORIDA TO YUCATAN PENINSULA TUE MORNING...AND FROM NEAR TAMPA BAY TO THE NE YUCATAN PENINSULA BY TUE EVENING WHERE IT BECOMES STATIONARY. MODELS THEN DEPICT THE WEAKENING FRONTAL BOUNDARY MORE LIKE A TROUGH FEATURE THAT PROPAGATES WESTWARD ACROSS THE CENTRAL GULF WED THROUGH THU BEFORE IT BECOMES RATHER SUBTLE AS IT CONTINUES WESTWARD TO THE WESTERN GULF SAT. BY LATE FRI...THE GFS BRINGS A WEAK FRONTAL BOUNDARY TO THE FAR NW GULF PORTION FOLLOWED BY STRONG HIGH THAT BUILDS SE BEHIND IT. THE OTHER GLOBAL MODELS...ARE A LOT DIFFERENT IN THE DEPICTION OF THIS BOUNDARY BY HOLDING IT BACK OVER THE MID-WEST AND NORTHERN TEXAS FRI AND SAT. FOR THIS FORECAST WILL HOLD OFF ON BRINGING THE NEXT FRONT INTO THE GULF...AND FOLLOW MODEL CONSENSUS ON FORECAST POSITION OF THE FRONT. SO WILL HOLD IT BACK NW OF THE AREA DAYS 4 AND 5. FOR SEAS...WILL CLOSELY FOLLOW THE NOAA WAVEWATCH GUIDANCE IN LOWERING SEAS TO 2-3 FT ENTIRE AREA WED INTO SAT. UNTIL THEN...THEN SEAS AHEAD AND BEHIND THE FRONT LOWER TO 4-6 FT TUE AND 2-3 FT WED. FOR THE REMAINDER OF AREA WILL CLOSELY FOLLOW THE NOAA WAVEWATCH GUIDANCE IN LOWERING SEAS TO 2-3 FT ENTIRE AREA WED INTO SAT UNDER WEAK HIGH PRES PATTERN. SOUTHWEST NORTH ATLC S OF 31N W OF 65W... THE 18 UTC PRELIMINARY SURFACE ANALYSIS REVEAL A RATHER WEAK HIGH PRES PATTERN OVER THE AREA HELD BY A RIDGE THAT EXTENDS FROM NEAR 25N65W SW TO 23N79W. A WARM FRONT/STATIONARY FRONTAL BOUNDARY IS JUST NW OF THE AREA FROM SOUTHEASTERN S CAROLINA ENE TO NEAR 34N75W. IN THE UPPER LEVELS...A LARGE DOME OF HIGH PRES COVERS JUST ABOUT THE ENTIRE BASIN...AND IS HELPING TO VENTILATE DEEP SCATTERED DEEP CONVECTIVE ACTIVITY S OF 28N BETWEEN 69W AND 80W INCLUDING THE BAHAMAS. BUOYS THROUGHOUT ALONG WITH A FEW SHIP OBSERVATIONS ARE REPORTING SLY WINDS OF 15-20 KT W OF ABOUT 70W...AND LIGHTER WINDS IN THE E-SE DIRECTION OF 10 KT E OF 70W WITH THE EXCEPTION OF THE FAR SRN WATERS E OF THE BAHAMAS WHERE A SLIGHTLY TIGHTER PRES GRADIENT IS ALLOWING FOR NE-E 10-15 KT THERE. OBSERVED SEA STATE HAS SEAS OF 3-4 FT E AND NE OF THE BAHAMAS...AND 2-3 FT SW OF THE BAHAMAS. THE 12 UTC GLOBAL MODEL RUNS SUGGEST THAT THE GULF OF MEXICO COLD FRONT WILL MOVE INTO THE FAR NW CORNER OF THE BASIN TUE NIGHT. WITH THE UPPER TROUGH LIFTING NE OVER THE SE UNITED DURING THE NEXT 48 HRS...THE FRONT WILL BEGIN TO SLOW DOWN AS IT PRESSES SE TO NEAR A POSITION FROM NEAR 31N78W TO CENTRAL FLORIDA WED WHILE BECOMING STATIONARY. THE SLY WINDS OF 15-20 KT ARE EXPECTED TO CONTINUE INTO TUE NIGHT BEFORE DIMINISHING TO 10-15 KT. SEAS BUILD TO 6-7 FT UNDER THE 15-20 KT WINDS PRIMARILY N OF 27N TUE...BUT THEN QUICKLY SUBSIDE TO 5-6 FT TUE NIGHT AND TO 3-4 FT WED. THE FRONT IS FORECAST TO BECOME DIFFUSE THU AS PRES BECOMES RE-ESTABLISHED NEAR 31N WITH AN ASSOCIATED HIGH CENTER OF ABOUT 1023MB-1025 MB...AND PRETTY MUCH DOMINATES THE BASIN THROUGH DAY 5 (SAT) MAINTAINING GENERALLY LIGHT WINDS THROUGHOUT. THE NORTHERN PORTION OF A TROPICAL WAVE THAT ENTERS THE EASTERN CARIBBEAN ON THU IS FORECAST TO SHEAR OFF INTO NE-SW ORIENTED TROUGH JUST SE OF THE AREA THU AND FRI AS A BACKDOOR TYPE FRONT DROPS S JUST TO THE NE OF THE FORECAST ATLC ZONES. THE PRES DIFFERENCE BETWEEN THE TROUGH AND A COLD FRONT TO ITS N AND NE MAY BRING N-NE WINDS OF 15-20 KT OVER THE FAR NE ZONE LATE THU AND FRI AS DEPICTED BY THE BNDRY LYR WIND FORECAST FROM GFS AND ECMWF MODEL FIELDS. SEAS THERE MAY INCREASE TO 5-6 FT PER GUIDANCE FROM THE NOAA WAVEWATCH III GUIDANCE. THESE WINDS THEN DIMINISH TO 10-15 KT ON SAT AS THEY VEER TO NE IN DIRECTION. WINDS ARE EXPECTED TO BECOME LIGHT AND VARIABLE IN THE FAR SE PORTION SAT NEAR THE TROUGH FEATURE THAT IS EXPECTED TO EVOLVE FROM THE TROPICAL WAVE TO THE S. THE CURRENT CLUSTERS OF STRONG CONVECTIVE CLUSTERS EVIDENT S OF 28N BETWEEN 69W AND 80W ARE EXPECTED TO SHIFT NW THROUGH WED NIGHT AND MERGE WITH REMNANT SHOWER/TSTM ACTIVITY LEFT OVER FROM THE DISSIPATING STATIONARY FRONT. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... AN UPPER LEVEL LOW OVER THE GULF OF HONDURAS IS ENHANCING NUMEROUS TSTM ACTIVITY OVER MUCH OF THE NW AND NORTHERN CARIBBEAN WATERS. CENTRAL ATLC HIGH PRES N OF THE AREA EXTENDS SW. THE PRES DIFFERENCE BETWEEN THE HIGH AND BROAD LOW PRES OVER THE MUCH OF THE WESTERN CARIBBEAN SEA IS RESULTING IN A BROAD SWATH OF NE-E 20-25 KT TRADES OVER THE CENTRAL PORTION OF THE SEA AS PARTIALLY CAPTURED BY THE HIGH RESOLUTION ASCAT PASS FROM JUST PAST 14 UTC THIS MORNING. THESE WINDS MATCH UP PRETTY WELL FROM GFS/ECMWF WIND GUIDANCE. TRADES ELSEWHERE ARE IN THE LIGHT TO MODERATE RANGE WITH SEAS OF 3-5 FT...EXCEPT 5-6 FT IN THE NORTHERN AND CENTRAL TROPICAL N ATLC AND 2-3 FT IN THE WESTERN CARIBBEAN EXCEPT IN AND NEAR THE TSTM ACTIVITY WHERE THEY MAY BE HIGHER. BUOY 42058 AT 15N75W IS REVEALING COMBINED SEAS OF 8 FT WITH SOME BRIEF MOMENTS AT 9 FT. FOLLOWING THE GFS AND ECMWF UPPER LEVEL GUIDANCE...THE UPPER LEVEL LOW WILL MOVE WNW THROUGH WED PULLING THE TSTMS W TO OVER THE FAR CARIBBEAN AND YUCATAN CHANNEL BY WED NIGHT. THE CENTRAL ATLC HIGH PRES SHIFTS NW THROUGH THU AND FRI ALLOWING FOR THE PRES GRADIENT TO WEAKEN OVER THE CENTRAL CARIBBEAN. AS A RESULT...THE NE-E 20-25 KT WINDS THERE DIMINISH TO 15-20 KT AND TO 10-15 KT FRI AND SAT. THE SEAS THERE SUBSIDE TO 3-5 FT FRI AND SAT. IN THE LONG TERM...A TROPICAL WAVE CURRENTLY E OF THE AREA OVER THE CENTRAL ATLC IS EXPECTED TO ENTER THE FAR EASTERN TROPICAL N ATLC TUE AFTERNOON...REACH TO NEAR 57W/58W BY WED MORNING...THEN MOVE ACROSS THE LESSER ANTILLES WED NIGHT AND THE EASTERN CARIBBEAN THU AND FRI AND CENTRAL CARIBBEAN PORTION SAT BY WHICH TIME IT SHOULD BE UNDER A MORE UNFAVORABLE UPPER LEVEL ENVIRONMENT MAKING IT LESS DISCERNIBLE AT THE SURFACE. UNTIL IT REACHES THE CENTRAL CARIBBEAN SEA...THE WAVE MAY LIKELY BE ACCOMPANIED BY SCATTERED SHOWERS AND TSTMS WITH GUSTY WINDS. 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 AGUIRRE