000 AGXX40 KNHC 171016 AAA MIMATS MARINE WEATHER DISCUSSION...UPDATED NWS NATIONAL HURRICANE CENTER MIAMI FL 516 AM EST THU DEC 17 2015 UPDATED GULF OF MEXICO COLD FRONT POSITION AND CARIBBEAN CONVECTION 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...UPDATED MODEL PREFERENCE: FOR WINDS USED BLEND OF 00 UTC GFS WITH PREVIOUS OFFICIAL FORECAST. WAVEHEIGHT GRIDS WERE WEIGHTED HIGHLY TOWARDS THE TAFB NWPS WAVE OUTPUT. HIGH CONFIDENCE. THE COLD FRONT THAT MOVE OFFSHORE THE TEXAS COAST YESTERDAY MORNING EXTENDS JUST W OF MOBILE BAY AND SE LOUISIANA SW TO 26N92W AND TO NEAR VERACRUZ AS OF 09 UTC THIS MORNING. E OF THE FRONT WEAK HIGH PRES IS SHIFTING EASTWARD WHILE STRONGER HIGH PRES IS BEHIND THE FRONT. THE BUOY OBSERVATIONS AND OFFSHORE OIL PLATFORMS ARE REPORTING MODERATE SE-S WINDS E OF THE FRONT...AND MODERATE TO STRONG N-NE WINDS WINDS BEHIND THE FRONT. SEAS RANGE FROM 2-3 FT E OF 90W...TO 3-5 FT W OF 90W EXCEPT FOR A POCKET OF HIGHER SEAS IN THE RANGE OF 6-7 FT OFF THE TEXAS COAST E TO ABOUT 95W AND FROM 25N-28N. THE COLD FRONT WILL REACH FROM NEAR MOBILE ALABAMA TO VERACRUZ MEXICO THIS MORNING...FROM NEAR NEAR APALACHICOLA FLORIDA TO 25N90W TO 24N92W TO THE SW GULF NEAR 18N94W EARLY THIS EVENING... THEN FROM NEAR TAMPA BAY FLORIDA SW 25N86W TO NEAR OR JUST ALONG THE NW YUCATAN PENINSULA AND TO THE EASTERN BAY OF CAMPECHE NEAR 18.5N93W FRI MORNING. THE FRONT WILL THEN EXIT THE SE GULF FRI EVENING. MODEL GUIDANCE STILL ON TRACK IN FORECASTING FRESH TO STRONG NORTHERLY FLOW SPREADING ACROSS THE GULF IN THE WAKE OF THE FRONT...BUT WINDS WILL BE EVEN STRONGER OFFSHORE OF VERACRUZ WHERE A GALE WARNING IS NOW IN EFFECT LASING INTO FRI. SEAS ARE FORECAST TO BUILD TO THE 10-15 FT RANGE AS FORECAST BY THE LATEST RUN OF THE TAFB NWPS WAVE MODEL. WINDS WILL DIMINISH ACROSS THE NW HALF OF THE BASIN AS THE HIGH PRES BEHIND THE FRONT BUILDS IN ACROSS THE SOUTHERN MISSISSIPPI VALLEY FRI NIGHT THROUGH SAT...WITH THE HIGH MOVING NE TO THE CAROLINAS BY SAT NIGHT INTO EARLY SUN. THIS WILL ALLOW FOR WINDS TO VEER AROUND TO THE E-SE IN DIRECTION OVER THE AREA BY EARLY ON SUN. A TIGHT GRADIENT BETWEEN THE FRONT OVER WESTERN CUBA AND THE NW CARIBBEAN AND STRONG HIGH PRES OVER THE CAROLINA REGION SAT NIGHT AND SUN WILL SUPPORT FRESH TO AT TIMES STRONG NE WINDS OVER MUCH OF THE EASTERN PORTION...AND STRAITS OF FLORIDA INTO EARLY SUN. THE WINDS THEN DIMINISH LATER ON SUN AND MON AS THE HIGH PRES SHIFTS EASTWARD OVER THE ATLC AND THE FRONTAL BOUNDARY OVER THE CARIBBEAN WEAKENS FURTHER. THE SEAS ASSOCIATED WITH THE FRESH TO STRONG NE WINDS ARE FORECAST TO BE IN THE 8-10 FT RANGE. MAX SEAS OF 10 FT WILL LINGER IN THE STRAITS INTO SUN AS THEY WILL BE SLOW IN SUBSIDING. THEY THEN SUBSIDE TO 6-8 FT LATE SUN INTO MON. WILL ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...UPDATED MODEL PREFERENCE: FOR WINDS USED BLEND OF 00 UTC GFS WITH PREVIOUS OFFICIAL FORECAST. FOR WAVEHEIGHTS USED A BLEND OF THE 00 UTC MWW3 WITH PREVIOUS OFFICIAL AND WITH A SMALL PERCENTAGE OF TAFB WAVE OUTPUT. HIGH CONFIDENCE. DIFFLUENCE ALOFT E OF AN UPPER TROUGH THAT EXTENDS FROM AN ELONGATED ATLC UPPER LOW NEAR 23N68W SW ACROSS HISPANIOLA AND TO NEAR 14N74W HAS BEEN PERSISTENT IN KICKING OFF CONVECTION WITH FREQUENT LIGHTNING STRIKES DURING THE PAST FEW DAYS IN HE CENTRAL CARIBBEAN S OF HISPANIOLA. THIS ACTIVITY HAS SHIFTED TO WITHIN 120 NM SE OF THE DOMINICAN REPUBLIC. IT IS FORECAST TO DIMINISH OVER THE NEXT DAY OR SO AS THE ATLC UPPER LOW MOVES E AND WEAKENS. A 1017 MB HIGH CENTER IS LOCATED N OF THE AREA IN THE ATLC NEAR 23N52W WHILE LOW PRES IS OVER NW COLOMBIA. THE PRES GRADIENT BETWEEN THESE TWO FEATURES CONTINUES TO SUPPORT FRESH TO LOCALLY STRONG TRADES IN THE CENTRAL CARIBBEAN AND RESULTANT SEAS IN THE RANGE OF 6-8 FT. OTHERWISE...MAINLY MODERATE TO LOCALLY FRESH E-SE WINDS PREVAIL ALONG WITH SEAS IN THE 3-5 FT RANGE W OF 77W EXCEPT FOR LOWER SEAS OF 2-3 FT S OF 76W...AND SEAS IN THE RANGE OF 5-6 FT E OF 68W INCLUDING THE TROPICAL N ATLC ZONES. CHANGES TO WINDS AND SEAS WILL BE ATTRIBUTED TO STRONG HIGH PRES BUILDING ACROSS MUCH OF THE ATLC BEGINNING TONIGHT AND THROUGH THE WEEKEND. THIS WILL ACT TO STRENGTHEN THE PRES GRADIENT ALLOWING FOR THE FRESH TO STRONG TRADES TO EXPAND AND SPREAD WESTWARD THROUGH THE FORECAST PERIOD. A STRONG COLD FRONT IS FORECAST TO MOVE SE OF THE YUCATAN CHANNEL FRI NIGHT WITH FRESH TO STRONG N-NE WINDS FOLLOWING THE FRONT WHICH WILL QUICKLY BUILD SEAS TO UP TO AROUND 10 OR 11 FT IN THE VICINITY OF THE CHANNEL LATE FRI NIGHT INTO SAT. THESE WINDS WILL GRADUALLY SPREAD S ACROSS THE NW CARIBBEAN THROUGH LATE SAT BEFORE SUBSIDING TO 8 FT SUN. THE FRONT WILL REACH FROM CENTRAL CUBA TO NW HONDURAS SAT MORNING...THEN FROM EASTERN CUBA TO EASTERN HONDURAS SAT EVENING WHERE IT WILL BECOME STATIONARY AND GRADUALLY BECOME DIFFUSE THROUGH SUN. GLOBAL MODEL GUIDANCE IS IN QUITE GOOD AGREEMENT REGARDING THE MOVEMENT AND PLACEMENT OF THE FRONT. THE FRESH TO STRONG WINDS WILL SPREAD EASTWARD IN THE WAKE OF THE FRONT WHILE VEERING TO THE NE-E AND DECREASING BY SUN AFTERNOON. AHEAD OF THE FRONT...THE PRES GRADIENT WILL BE RELATIVELY TIGHT WITH FRESH TO STRONG TRADES...POSSIBLY TO GALE FORCE NEAR THE NW COAST OF COLOMBIA BY LATE SAT NIGHT INTO SUN...AND AGAIN LATE ON SUN NIGHT. WILL UPDATE WIND GRIDS AS NECESSARY. WINDS WILL DIMINISH AND TURN E-SE IN THE NW CARIBBEAN MON AS HIGH PRES RIDGING BUILDS N OF THE AREA. IN THE TROPICAL N ATLC...GENTLE TO MODERATE TRADES WILL INCREASE TO FRESH FRI NIGHT OVER THE EASTERN PORTION AS THE PRES GRADIENT TIGHTENS AND OVER MUCH OF THE AREA BY MON. A MAJOR LONG PERIOD NE SWELL EVENT WILL OCCUR ACROSS THESE WATERS BEGINNING THU NIGHT AND THROUGH THE WEEKEND AND EVEN INTO EARLY NEXT WEEK WITH 8-11 FT SIGNIFICANT WAVE HEIGHTS EXPECTED. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: FOR WINDS USED BLEND OF 00 UTC GFS WITH PREVIOUS OFFICIAL FORECAST. FOR WAVEHEIGHTS USED A BLEND OF THE 00 UTC MWW3 WITH PREVIOUS OFFICIAL AND WITH A SMALL PERCENTAGE OF TAFB WAVE OUTPUT. HIGH CONFIDENCE. A WEAK HIGH PRES CENTER OF 1017 MB IS ANALYZED NEAR 25N63W WHILE A 1018 MB HIGH IS NEAR 29N72W. A BACKDOOR FRONT IS ALONG 29N E OF 70W. OBSERVATIONS INDICATE MAINLY GENTLE TO MODERATE ANTICYCLONIC FLOW ACROSS THE BASIN. THE CURRENT BUOY OBSERVATIONS ALONG WITH A FEW RECENT AND CURRENT SHIP OBSERVATIONS AND RECENT ALTIMETER DATA PASSES REVEAL SEAS IN THE 3-5 FT RANGE OUTSIDE OF THE BAHAMAS...EXCEPT 4-6 FT IN THE NE PART AND LOWER SEAS OF 1-2 FT W OF THE BAHAMAS. THE WEAK HIGH PRES OVER THE BASIN WILL BE REPLACED BY STRONGER CENTRAL ATLC HIGH PRES THAT SLIDES E OVER THE EASTERN PORTION TODAY THROUGH FRI IN RESPONSE TO THE NEXT COLD FRONT THAT MOVES OFF THE SE U.S COAST. ASSOCIATED MODERATE SE-S FLOW WITH THE HIGH PRES WILL BE PRESENT E OF THE BAHAMAS. THE FRONT WILL MOVE OFF THE NE FLORIDA AROUND 12 UTC FRI. IT WILL REACH A POSITION FROM NEAR 31N74W TO JUST SE OF S FLORIDA AND TO NW CUBA FRI EVENING...FROM NEAR 31N68W TO N CENTRAL CUBA EARLY ON SAT...THEN FROM NEAR 27N65W TO EASTERN CUBA EARLY ON SUN WHERE IT WILL STALL AND GRADUALLY BECOME DIFFUSE THROUGH MON. FRESH TO STRONG SOUTHERLY WINDS WILL SPREAD EASTWARD N OF 29N AHEAD OF THE FRONT...WITH FRESH TO STRONG NORTHERLY WINDS BEHIND IT. THE WINDS WILL DIMINISH IN THE NW PORTION BY SUN MORNING AS HIGH PRES BECOMES CENTERED OVER THE CAROLINAS IN THE WAKE OF THE FRONT. THE FRESH TO STRONG WINDS WILL GRADUALLY VEER AROUND TO THE NE-E SUN ACROSS THE REMAINDER OF THE BASIN WITH SEAS OF 7-10 FT EXPECTED NE AND E OF THE BAHAMAS. CONDITIONS WILL BE MOST HAZARDOUS IN AND NEAR THE GULF STREAM AND STRAITS OF FLORIDA AS COUNTER FLOW OF CURRENT TO THE NE WINDS WILL MAINTAIN SEAS THERE OF 8-9 FT THROUGH LATE SUN AFTERNOON. THE HIGH CENTER WILL SHIFT WELL TO THE E BY EARLY NEXT WEEK WITH RIDGING DOMINATING THE BASIN BY THEN. EXPECT MODERATE TO FRESH RETURN FLOW N OF 22N AND FRESH TO LOCALLY STRONG E-SE WINDS S OF 22N FOR THE START OF NEXT WEEK. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... .GMZ023...SW GULF S OF 22N W OF 94W... GALE WARNING TONIGHT INTO FRI. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.