000 AGXX40 KNHC 121906 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 305 PM EDT SAT SEP 12 2015 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. HIGH CONFIDENCE. AN AUTUMN LIKE PATTERN IS SETTING UP OVER THE REGION AS A RATHER STRONG MID/UPPER TROUGH IS NOTED TO STRETCH FROM THE OHIO VALLEY SW TO TO THE NW AND NE CENTRAL GULF PORTIONS. THIS TROUGH SUPPORTS A COLD FRONT THAT HAS NOW PUSHED SE ACROSS THE GULF ALONG A LINE FROM THE WESTERN FLORIDA PANHANDLE SW TO 28N93W TO INLAND SOUTHERN TEXAS. A PRE-FRONTAL TROUGH EXTENDS FROM NE FL SW TO 27N89W TO 25N94W TO THE FAR SW GULF. UPPER DIFFLUENCE FLOW ALOFT BETWEEN THE TROUGH AND AN UPPER ANTICYCLONE OVER CENTRAL MEXICO IS PROVIDING A FAVORABLE ENVIRONMENT FOR DEEP CONVECTION TO PERSIST ALONG AND WITHIN 90 NM SE OF THE PRE-FRONTAL TROUGH. EXTENSIVE AREAS OF LIGHT TO MODERATE PRECIPITATION ARE NOTED BEHIND THE DEEP CONVECTION NW TO ALONG A LINE FROM 30N92W TO 28N97W. THE WESTERN EXTENSION OF A WEAK ATLC RIDGE EXTENDS INTO THE EASTERN GULF NEAR 23N E OF 86W. CURRENT BUOY OBSERVATIONS ARE REPORTING GENTLE SW 10-15 KT WINDS E OF THE TROUGH...WHILE N-NE 10-15 KT WINDS TO THE NW OF THE FRONT. THE BUOYS AND RECENT ALTIMETER DATA INDICATE THAT SEAS ARE IN THE 2-3 FT RANGE W OF 86W...AND 1-2 FT E OF 86W. THE FORECAST FOR WILL HAVE LITTLE IN THE WAY OF CHANGES FROM PREVIOUS ONES. THE FRONT WILL REACH FROM W CENTRAL FLORIDA SW TO NEAR 25N91W...AND BECOME WEAKENING STATIOANRY TO INLAND NE MEXICO BY EARLY SUN. WINDS BEHIND THE FRONT WILL INCREASE TO THE MODERATE RANGE FROM THE NE IN DIRECTION OVER THE N CENTRAL GULF WITH SEAS IN THE 3-4 FT RANGE. WITH THE UPPER SUPPORT PULLING AWAY FROM THE AREA LATER SUN AND INTO MON...THE FRONT WILL ONLY NUDGE A LITTLE TO THE S THROUGH SUN NIGHT...AND BECOME STATIONARY FROM NEAR FORT MYERS TO 26N89W TO NEAR THE NE MEXICO AND S TEXAS BORDER BY EARLY MON. HIGH PRESSURE WILL BUILD SWD OFF THE MID-ATLC COAST SUN AND MON WITH ASSOCIATED RIDGING BRIDGING ACROSS THE STATIONARY FRONT INTO TUE. THE WESTERN PORTION OF THE FRONT WILL LIFT N AS A WARM FRONT MON AND TUE AS SELY FLOW...MAINLY IN THE GENTLE RANGE ON THE SW PERIPHERY OF THE RIDGE...SETS UP OVER THE WESTERN GULF. WHILE THIS TAKES PLACE...THE NORTHERN END OF A TROPICAL WAVE WILL MOVE ACROSS THE SW GULF MON AND TUE. ANOTHER TROPICAL WAVE IS FORECAST TO PASS ACROSS THE STRAITS OF FLORIDA TUE AND WED AND ACROSS THE CENTRAL GULF WATERS THU. A TIGHT PRES GRADIENT BETWEEN THE WAVE AND THE AFOREMENTIONED ATLC HIGH PRES WILL BRING E-SE 15-20 KT WINDS BEHIND THE WAVE WITH SEAS IN THE 3-5 FT RANGE. A THERMAL TROUGH WILL DEVELOP EACH AFTERNOON OVER THE YUCATAN PENINSULA. THE TROUGH WILL MOVE W-NW INTO THE SW GULF WATERS DURING THE EVENING THROUGH LATE NIGHT HOURS...THEN DISSIPATE BY LATE IN THE MORNING HOURS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. HIGH CONFIDENCE. THE TROPICAL WAVE...REMNANTS OF TROPICAL CYCLONE GRACE...IS ALONG 69W N OF 13N MOVING W NEAR 15 KT. LATEST SATELLITE IMAGERY SHOWS THAT CONVECTION EARLIER NOTED WITH THE WAVE HAS DIMINISHED DURING THE DAY. THE 1442Z ASCAT PASS REVEALED LIGHTER WINDS E OF THE WAVE COMPARED TO THAT NOTED YESTERDAY. THE WAVE WILL MOVE TO VICINITY WINDWARD PASSAGE SUN NIGHT...THEN WEAKEN AS IT MOVES THROUGH CUBA MON THROUGH WED. A THIRD TROPICAL WAVE WILL MOVE INTO THE TROPICAL N ATLC BY SUN NIGHT...REACH THE EASTERN CARIBBEAN BY TUE AND THE CENTRAL CARIBBEAN WED AND THU. NE-E 20-25 KT WINDS ARE FORECAST TO BEGIN IN THE S CENTRAL CARIBBEAN TONIGHT...AND GRADUALLY EXPAND NORTHWARD THROUGH EARLY NEXT WEEK WITH SEAS OF 8-10 FT. THESE WINDS WILL THEN DIMINISH WED AND THU WITH SEAS SUBSIDING TO 5-6 FT BY THU. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. HIGH CONFIDENCE. THE PRELIMINARY 18Z SURFACE ANALYSIS HAS A RIDGE EXTENDING FROM NEAR 26N65W SW TO THE CENTRAL BAHAMAS. SCATTERED SHOWERS AND TSTMS HAVE ENTERED THE NW PORTION OF THE AREA. THE NORTHERN PORTION OF A CARIBBEAN TROPICAL WAVE IS S OF 20N ALONG 68W. THE LATEST ASCAT PASS FROM THIS MORNING HIGHLIGHTED E-SE WINDS 20 KT WITHIN ABOUT 60 NM E OF THE WAVE. CURRENT BUOY OBSERVATIONS AND EARLIER ALTIMETER DATA SHOW RELATIVELY LOW SEAS OF 2-3 FT E OF THE BAHAMAS...AND 1-2 FT W OF THE BAHAMAS. THE RIDGE WILL SHIFT S AHEAD OF A COLD FRONT...CURRENTLY ACROSS THE GULF OF MEXICO... EXPECTED TO MOVE OFF THE SE GEORGIA COAST EARLY SUN. THE FRONT WILL STRETCH FROM NEAR 31N75W TO E CENTRAL FLORIDA BY SUN AFTERNOON...AND WEAKEN MON AFTERNOON AS IT STALLS FROM NEAR 31N73W TO VERO BEACH FLORIDA...AND SLOWLY BECOME DIFFUSE THROUGH WED. THE NORTHERN END OF THE TROPICAL WAVE WILL REACH THE SE BAHAMAS SUN EVENING AND THE CENTRAL BAHAMAS MON EVENING BEFORE PASSING THROUGH THE STRAITS OF FLORIDA. WEAK HIGH PRES WILL WITH LOW SEAS WILL DOMINATE THE AREA WED AND THU. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER AGUIRRE. NATIONAL HURRICANE CENTER.