000 AGXX40 KNHC 221859 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT SAT SEP 22 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... LATEST BUOY AND OIL PLATFORM OBSERVATIONS FROM AROUND THE GULF CONTINUE TO REVEAL E-SE WINDS OF 10 KT THROUGHOUT MUCH OF THE GULF...EXCEPT FOR THE FAR NE PORTION WHERE N-NE WINDS OF 5-10 KT ARE OBSERVED. THE 1530 UTC HIGH RESOLUTION ASCAT PASS FROM THIS SHOWED THESE WINDS AS WELL. THE SEA HEIGHT REPORTS FROM THE BUOYS HAVE VARIED VERY LITTLE SINCE YESTERDAY SHOWING SEAS. THE SURFACE ANALYSES FROM THIS MORNING AND EARLY AFTERNOON DEPICT RATHER WEAK HIGH PRES ACROSS THE NORTHERN AND CENTRAL PORTIONS OF THE GULF...AND THE NORTHERN PORTION OF A TROPICAL WAVE OVER THE FAR SRN PORTION S OF ABOUT 22N AND ALONG 89W. A WEAK TROUGH STILL LINGERS IN THE SW PART OF THE GULF FROM 24N96W TO 19N93W... WHILE IN THE UPPER LEVELS...PERSISTENT BROAD SCALE TROUGHING IS PRESENT OVER THE WESTERN PORTION OF THE GULF. THESE FEATURES CONTINUE TO AID IN THE PRODUCTION OF ABUNDANT DEEP ATMOSPHERIC MOISTURE AND SCATTERED SHOWERS AND TSTMS OVER THE WESTERN PORTION OF THE SW GULF...ALTHOUGH MUCH LESS IN COVERAGE SINCE 24 HRS AGO. THE UPPER TROUGH WILL GRADUALLY LIFT NE THROUGH EARLY NEXT ALLOWING FOR A MORE ZONAL TO SETTLE IN AND SURFACE HIGH PRES TO BUILD S ACROSS MAINLY THE ACROSS THE NORTHERN AND CENTRAL GULF WATERS. THE SURFACE TROUGH IN THE SURFACE GULF WILL DISSIPATE THROUGH SUN. A WEAK COLD FRONT WILL SWEEP ACROSS THE EASTERN GULF SUN NIGHT AND MON LEADING THE SURGE OF THE HIGH PRES BUILDING S. WINDS BECOME NE-E 10-15 KT ACROSS MUCH OF THE ZONES OF THE NORTHERN AND CENTRAL GULF SUN NIGHT THROUGH TUE WITH A BRIEF INSTANCE OF N-NE WINDS OF 15-20 KT IN THE NE PART OF THE GULF SUN NIGHT AND MON BEFORE DIMINISHING TO 10-15 KT. WINDS BECOME NE-E 10-15 KT THROUGHOUT MUCH OF THE GULF DURING TUE AND WED. SEAS REMAIN RATHER LOW...EXCEPT FOR SEAS BUILDING TO 3-5 FT IN THE NE PART OF THE GULF SUN NIGHT THEN SUBSIDING TO 2-3 FT MON THROUGH THU. THE TROPICAL WAVE ALONG 89W WILL GRADUALLY BECOME LOSE ITS CHARACTERISTICS OVER THE BAY OF CAMPECHE MON WITH SCATTERED SHOWERS AND TSTMS IN ITS VICINITY DIMINISHING EARLY NEXT WEEK. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... THE PRELIMINARY 18 UTC SURFACE ANALYSIS HAS A SURFACE TROUGH EXTENDING FROM NEAR 31N74W SW TO THE NW BAHAMAS. EXTENSIVE DEEP MOISTURE CONTINUES TO STREAM NEWD FROM THE GULF OF MEXICO TO ACROSS THE FLORIDA PENINSULA...AND TO NEAR 74W IN ADVANCE OF THE UPPER TROUGH OVER THE WESTERN GULF OF MEXICO. AS A RESULT OF THE ATMOSPHERIC INSTABILITY...SCATTERED TO NUMEROUS SHOWERS AND TSTMS WITH POSSIBLE GUSTY WINDS ARE OCCURRING OVER MUCH OF THE WESTERN PART OF THE AREA OFFSHORE THE FLORIDA PENINSULA TO N AND NE OF THE BAHAMAS. ELSEWHERE WEAK HIGH PRES IS PRESENT OVER MUCH OF THE ZONE W OF ABOUT 70W. BOTH ASCAT DATA AND BUOY REPORTS ARE SHOWING RELATIVELY LIGHT WINDS THROUGHOUT...MAINLY FROM THE NE IN DIRECTION. SEAS ARE 2-3 FT...EXCEPT FOR 4-5 FT IN A NE SWELL E OF 72W AS BUOY 41047 AT 27.5N71.5W IS SHOWING. LATEST SUITE OF MODELS ARE IN REASONABLE AGREEMENT THAT A COLD FRONT MOVES INTO THE NW PORTION SUN MORNING. THE FRONT WILL THEN SLOW DOWN AS IT REACHES A POSITION FROM NEAR 31N76W TO WEST PALM BEACH EARLY SUN EVENING...THEN BECOME QUASI-STATIONARY AND BEGIN TO BECOME DIFFUSE AS HIGH PRES BUILDS S OVER THE AREA IN ITS WAKE. THE FRONT WILL SLOWLY DISSIPATE THROUGH TUE. GFS/ECMWF 10 M AND BOUNDARY LAYER WIND GUIDANCE IN AGREEMENT THAT WINDS BEHIND THE FRONT WILL BE FROM THE NW-N AROUND 10 KT EARLY SUN THEN INCREASE TO 10-15 KT AS THEY QUICKLY SHIFT TO THE NE-E LATER ON SUN AND SUN NIGHT...AND BECOME MORE ELY IN DIRECTION MON NIGHT THROUGH THUD AT 10-15 KT. LITTLE CHANGE WILL BE EXPECTED WITH SEAS INTO DAY 5 (WED) WITH ONLY A SLIGHT INCREASE POSSIBLE IN THE FAR NW AND SE WATERS MON NIGHT AND INTO WED. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... GENTLE TO MODERATE TRADE WINDS PREVAIL ACROSS THE CARIBBEAN WATERS AND THE TROPICAL N ATLC WATERS...EXCEPT FOR FRESH NE-E WINDS IN THE S CENTRAL CARIBBEAN WATERS WHERE SEAS ARE UP TO 8 FT. SEAS ELSEWHERE ARE IN THE 3-5 FT RANGE...EXCEPT 2-3 FT BETWEEN 19N AND CUBA. WITH THE PERSISTENCE OF THE FRESH NE-E WINDS IN THE S CENTRAL PORTION EXPECT SEAS THERE TO BUILD TO 9 OR 10 FT...FOLLOWING THE NWWIII AND NAH MODEL GUIDANCES...AND ALSO THE NWWIII/FNMOC ENSEMBLE PROBABILITY GUIDANCE...OVER THE NEXT 24 TO 48 HRS BEFORE SUBSIDING AGAIN. THE ECMWF WAVE GUIDANCE APPEARS TOO LOW FOR THAT PART OF THE CARIBBEAN. THE NEXT TROPICAL...CURRENTLY E OF THE TROPICAL N ATLC FROM 15N45W TO 10N51W...IS FORECAST TO MOVE INTO THE TROPICAL N ATLC WATERS SUN EVENING AND MON...ACCOMPANIED BY A BROAD LOW LEVEL WIND SURGE AND A SMALL POCKET OF SEAS UP TO 9 FT. THE WAVE SHOULD MOVE THROUGH THE EASTERN CARIBBEAN SEA TUE...THEN ACROSS THE CENTRAL CARIBBEAN WED AND THU FOLLOWING MORE CLOSELY THE ECMWF 850 MB VORTICITY FIELD GUIDANCE FOR THE WAVE FORECAST VERSUS THE GFS WHICH TENDS TO LOSE IT EARLIER IN THE 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 AGUIRRE