000 AGXX40 KNHC 111942 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 240 PM EST SUN NOV 11 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 RIG PLATFORMS REVEAL A VERY PRONOUNCED AND DEEP MOIST SLY FLOW CONSISTING OF SE-S WINDS OF 20-25 KT OVER THE BASIN N OF 25N AND W OF 87W. THE ASCAT PASS FROM 1634 UTC ALSO CONFIRMED THESE WIND CONDITIONS. SEAS THERE ARE BEING REPORTED IN THE 8-12 FT RANGE WITH THE 12 FT MAXES AT 27N94W AND AT BUOY 42020 AT 27N97W. ELSEWHERE THE BUOY OBSERVATIONS ALONG WITH A FEW SHIP REPORTS ARE INDICATING LIGHTER E-SE WINDS OF 15-20 KT...EXCEPT A NARROW SWATH OF E-SE 20-25 KT WINDS THROUGH THE STRAITS OF FLORIDA AND FAR SE GULF WATERS WITH SEAS OF 6-7 FT...EXCEPT TO 9 FT IN THE SE PORTION AND STRAITS OF FLORIDA. BOTH SATELLITE IMAGERY AND LATEST RADAR IMAGERY SHOW THE PATCHES OF MOISTURE IN THE SLY FLOW QUICKLY LIFTING N OVER THE NW GULF SECTION...AND LIFTING NW IN THE SRN PORTION OF THE MIDDLE AND EASTERN GULF SECTIONS. THESE PATCHES OF MOISTURE CONTAIN SCATTERED SHOWERS AND ISOLATED WEAK TSTMS...PARTICULARLY IN THE NW ZONE. THIS SLY FLOW IS FOUND ON THE SW PERIPHERY OF A STRONG EASTERN U.S. RIDGE THAT STRETCHES SW OVER THE SE STATES AND TO THE MIDDLE GULF. THIS RIDGE WILL SHIFT EASTWARD OVER THE NEXT 48 HRS ALLOWING FOR SURFACE LOW PRES AND AN ASSOCIATED COLD FRONT CURRENTLY OVER THE MID-WEST PORTION OF THE CONUS TO ADVANCE EASTWARD. THE SUPPORTING LARGE UPPER TROUGH WILL MOVE TO THE EASTERN PORTION OF THE COUNTRY BY TUE NIGHT. MODELS IN GENERAL GOOD AGREEMENT THAT THIS COLD FRONT WILL REACH THE TEXAS COAST LATE TONIGHT...AND INTO THE NW OFFSHORE GULF DURING MON MORNING. THE MODELS ARE ALSO IN GOOD AGREEMENT THAT STRONG NLY WINDS WILL FOLLOW IN BEHIND THE FRONT AS A STRONG HIGH CENTER...SIMILAR TO THE PRES ONE RESPONSIBLE FOR THE E COAST RIDGING...SHIFTS ENE ACROSS THE SRN PLAINS STATES AND MID-WEST REGION OF THE COUNTRY. EXPECT N-NE WINDS OF 20-25 KT BEHIND THE FRONT IN THE GULF BEGINNING MON. THE FRONT WILL RAPIDLY MOVE E TO A PSN FROM THE FLORIDA BIG BEND AREA SW TO THE WESTERN FLORIDA PANHANDLE SW TO NEAR VERACRUZ MEXICO BY EARLY MON EVENING...FROM NE FLORIDA AND BIG BEND AREA TO SW WESTERN BAY OF CAMPECHE BY TUE MORNING...THEN BEGIN TO WEAKEN FROM TAMPA FLORIDA TO THE SW GULF LATER ON TUE AS THE UPPER TROUGH SUPPORT CONTINUES TO PULL FURTHER NE AWAY FROM THE REGION. THE FRONT WILL SLOWLY DISSIPATE AS IT SAGS S FROM THE FAR SE GULF TO S CENTRAL FLORIDA LATER ON TUE AND INTO FRI. THE N-NE 20-25 KT WINDS BEHIND THE FRONT WILL SPREAD E TO COVER JUST ABOUT THE ENTIRE NW AND MIDDLE GULF SECTIONS BY LATE TUE AFTERNOON BEFORE DIMINISHING TO 15-20 KT DURING TUE NIGHT AND WED AS HIGH PRES TO THE N OF THE GULF SLIDES E. WINDS IN THE FAR SW PART OF THE GULF WILL BE FROM THE NW TO N IN DIRECTION AT 20-25 KT WITH POSSIBLE WINDS OF 25-30 KT NEAR THE COAST OF MEXICO LATE TUE AND WED BEFORE DIMINISHING TO 20-25 KT NEAR THAT COAST LATE WED AND THU...AND TO 10-15 KT ELSEWHERE IN THE SW PART OF THE GULF THU. ALSO BY THU AND INTO FRI...WINDS ELSEWHERE ACROSS THE AREA WILL HAVE BECOME NE AT 10-15 KT. FOR SEAS...SEA STATE CONDITIONS FROM THIS MORNING AND EARLY AFTERNOON WERE PRETTY NEAR TO NWWIII MODEL GUIDANCE...ECMWF AND UKMET WAVE GUIDANCE ALL ZONES WITH THE EXCEPTION OF THE NW ZONE WHERE MAX SEA HEIGHTS OF 12 FT ARE ABOUT 2 FT ABOVE THESE GUIDANCES BUT CLOSEST TO GUIDANCE FROM THE NAH. FOR THIS FORECAST WILL FOLLOW A BLEND OF THE NAH/ECMWF AND NWWIII WITH MORE RELIABILITY ON THE NAH AND UKMET FOR GUIDANCE IN THE SW GULF BEHIND THE FRONT. BY THU ALL GUIDANCES IN VERY GOOD AGREEMENT THAT SEAS SUBSIDE TO 3-5 FT...EXCEPT FOR 5-7 FT IN THE W PART OF THE SW ZONE BEFORE SUBSIDING TO 4-5 FT BY LATE THU AND TO 3-5 FT FRI N OF 21N...AND TO 2-3 FT S OF 21N. SOUTHWEST NORTH ATLC S OF 31N W OF 65W... THE 18 UTC PRELIMINARY SURFACE ANALYSIS HAS TIGHT ISOBAR SPACING OVER THE WESTERN PORTION OF THE BASIN...AND A STATIONARY FRONTAL SYSTEM THAT STRETCHES FROM NEAR 31N52W SW TO 24N60W WHERE IT BEGINS TO DISSIPATE TO NEAR 19N68W. THE ASCAT PASS FROM 1452 UTC THIS MORNING REVEALED A LARGE SWATH OF NE 20-25 KT WINDS BETWEEN THE FRONT AND THE BAHAMAS. STEADY E WINDS OF 20 KT ARE NOTED FROM THE BAHAMAS TO STRAITS OF FLORIDA. BUOYS ALONG WITH A FEW SHIP OBSERVATIONS ARE SHOWING NE-E 20 KT THROUGHOUT...WITH SHIP REPORTS OF N-NE WINDS OF 20-25 KT WITHIN 150 NM NW OF THE FRONT. THE REPORTS ARE INDICATING SEAS OF 8-11 FT IN A NE SWELL BETWEEN THE FRONT AND THE BAHAMAS...AND 8 FT TO THE N AND SW OF THE BAHAMAS. SCATTERED SHOWERS AND TSTMS...AIDED BY AN UPPER LEVEL TROUGH...ARE CONFINED TO THE FAR SE WATERS ALONG AND NEAR THE WEAK FRONTAL BOUNDARY. FOR THIS FORECAST PACKAGE WILL KEEP CONSISTENCY WITH RECENT ONES IN FORECASTING U.S. E COAST HIGH PRES TO BEGIN TO SHIFT EASTWARD TONIGHT THROUGH TUE WHILE WEAKENING. THIS WILL ALLOW FOR THE APPROACHING GULF OF MEXICO COLD FRONT TO ENTER THE FAR NW WATERS TUE AFTERNOON BEFORE SLOWING DOWN. THE FRONT WILL THEN DRIFT S TO A PSN FROM THE NW BAHAMAS TO CENTRAL FLORIDA TUE AND TUE NIGHT WHILE DISSIPATING. THE STATIONARY FRONT OVER THE SE WATERS WILL GRADUALLY WEAKEN INTO A TROUGH THROUGH WED AS IT MOVES WESTWARD TOWARDS THE SE BAHAMAS THU...THEN DAMPENS LATER THU AND FRI. WINDS BEHIND THE COLD FRONT OVER THE NW PORTION ARE EXPECTED TO BECOME NE 20 KT TUE THROUGH THROUGH FRI WITH SEAS TO 8 FT. WINDS AND SEAS ELSEWHERE DIMINISH WED THROUGH FRI...HOWEVER NE SWELLS WILL ALLOW FOR SEAS OF 6-8 FT TO PLAGUE MOST OF THE BASIN EXCEPT SW OF THE BAHAMAS DURING THE MIDDLE TO LATTER PART OF THE WEEK. SEAS SW OF THE BAHAMAS SUBSIDE TO 4-6 FT MON NIGHT INTO TUE AND CONTINUE AT THAT RANGE THROUGH FRI. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... STRONG WESTERN ATLC HIGH PRES CONTINUES TO SUPPORT A TIGHT PRES GRADIENT OVER THE WESTERN AND CENTRAL CARIBBEAN ALLOWING FOR NE-E WINDS OF 20-25 KT THERE N OF ABOUT 11N. THE SEA STATE ANALYSIS FROM THIS MORNING ALONG WITH RECENT BUOY OBSERVATIONS HAVE SEAS OF 8-10 FT OVER THE CENTRAL AND SW PORTIONS OF THE SEA. SEAS TO 9 FT IN A NE SWELL ARE BEING REPORTED BY BUOYS IN THE TROPICAL N ATLC. WITH THE ATLC RIDGE FORECAST TO SHIFT E AND WEAKEN AS STATED ABOVE...EXPECT THESE WIND AND SEAS CONDITIONS TO LOWER THROUGH THE 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