000 AGXX40 KNHC 171806 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 106 PM EST WED DEC 17 2014 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 FORECAST. 12Z TAFB-NWPS USED WAVE HEIGHTS. HIGH CONFIDENCE. 12Z SYNOPTIC ANALYSIS SHOWS A STATIONARY FRONT EXTENDING FROM TAMPA BAY SW TO 25N90W THEN BECOMING A WARM FRONT TO BROWNSVILLE TEXAS. THIS FRONT BRIDGES BROAD HIGH PRES ACROSS THE SOUTHERN GULF WATERS AND A SLIGHTLY STRONGER RIDGE TO THE NORTH OF THE FRONT ACROSS THE LOWER MISSISSIPPI RIVER VALLEY AND FAR NORTHERN GULF WATERS. LATEST OBSERVATIONS AND SCATTEROMETER DATA INDICATES GENTLE ANTICYCLONIC WINDS N OF 26N WITH BROADER ANTICYCLONIC FLOW IN GENTLE TO MODERATE FLOW S OF THE WEAKENING BOUNDARY. SEAS REMAIN GENERALLY IN THE 1-3 FT RANGE WITH A SLIGHT UPTICK IN SEAS OF 2-4 FT ACROSS THE NW AND WEST-CENTRAL ZONES IN AN AREA OF RE-ESTABLISHING RETURN FLOW. WITH REGARDS TO RETURN FLOW BEGINNING ACROSS PORTIONS OF THE WESTERN GULF...MODELS ARE IN GOOD AGREEMENT THROUGH FRI THAT THE WARM FRONT WILL LIFT N ACROSS SOUTHERN TEXAS AND THE ADJACENT COASTAL WATERS THU INTO FRI WITH CYCLOGENESIS OCCURRING ALONG THE TEXAS COAST...AND A NEWLY FORMED LOW MOVING NE INTO SAT LOCATING ITSELF NEAR MOBILE BAY. THE ASSOCIATED COLD FRONT WILL DRAPE S-SW FROM THE LOW AND QUICKLY MOVE ACROSS THE GULF EXTENDING FROM THE WESTERN GULF FRI LATE AND NIGHT...THEN TO THE FLORIDA PANHANDLE TO EASTERN BAY OF CAMPECHE SAT NIGHT...AND WEAKEN AS IT REACHES FROM CEDAR KEY TO 24N88W SUN. BETTER AGREEMENT IS NOTED IN THE LATEST GLOBAL MODEL RUNS WITH TIMING AND FORECAST POSITIONS. THE MAIN DIFFERENCE WITH THE MODELS NOTED WITH THIS NEXT SYSTEM IS WIND SPEEDS BEHIND THE FRONT ACROSS THE WESTERN GULF FRI AFTERNOON THROUGH EARLY ON SAT. MOST MODELS AGREE WITH NLY WINDS OF 10-15 KT BEHIND THE FRONT WITH THE EXCEPTION OF THE ECMWF AND UKMET GUIDANCE DEPICTING WINDS OF 20 KT. BLENDED WIND GRIDS RESULT IN A 15-20 KT WINDS BEHIND THE FRONT FOR THOSE TIME PERIODS AS IT APPEARS THAT SURFACE HIGH PRES BUILDING IN THE WAKE OF THE FRONT WILL BE A BIT STRONGER THAN THE CURRENT HIGH PRES IN PLACE. THE COMBINATION OF THIS ALONG WITH THE LOW PRES TAKING MORE OF A TRACK FARTHER S ALONG THE COASTAL PLAINS THE RESULTANT PRES WILL BE SUFFICIENT TO SUPPORT THESE WINDS. THE WINDS WILL DIMINISH QUICKLY DURING SAT AFTERNOON AND EVENING AS THE LOW RACES NE FAR AWAY FROM THE REGION AND THE HIGH PRES WEAKENS AS WELL. THE SUPPORT FOR THE FRONT WILL BE UNFAVORABLE AT THAT TIME TO SUPPORT A SUSTAINABLE FRONTAL BOUNDARY...SO WILL FORECAST THE FRONT AS STATED EARLIER. SEAS THERE ARE EXPECTED TO PEAK UP TO 5 FT...ACROSS PORTIONS OF THE WESTERN GULF NEAR THE TEXAS COAST LATE FRI AND SAT BEFORE SUBSIDING ONCE AGAIN. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. 12Z TAFB-NWPS USED FOR WAVE HEIGHTS. HIGH CONFIDENCE. 12Z SYNOPTIC ANALYSIS INDICATES A RIDGE EXTENDING SEWD FROM THE SW GULF OF MEXICO TO NORTHERN NICARAGUA. THE INDUCED PRES GRADIENT HAS TIGHTEN SOMEWHAT SINCE YESTERDAY ALLOWING FOR NORTHERLY WINDS IN THE 20-25 KT RANGE OFF THE COAST OF NICARAGUA. AN EARLIER ASCAT PASS CONFIRMED THIS WIND FIELD WHICH STRETCHES TO THE NORTH ACROSS THE NW CARIBBEAN TO THE NW OF A SHEAR LINE FROM JAMAICA TO 15N81W. THE SAME SWATH OF SCATTEROMETER DATA ALSO SHOWED NE WINDS FUNNELING THROUGH THE WINDWARD PASSAGE AND THE SOUTHERN ADJACENT COASTAL WATERS OF HISPANIOLA. THE PRES GRADIENT IS EXPECTED TO RELAX SOMEWHAT DURING THE NEXT 24 HOURS TO ALLOW FOR THE WINDS NEAR THE COAST OF CENTRAL AMERICA TO DIMINISH...HOWEVER THE NE 20 KT WINDS FROM 15N-19N BETWEEN JAMAICA AND 82W AND THROUGH THE WINDWARD PASSAGE SHOULD PERSIST THROUGH THU MORNING. ELSEWHERE ACROSS THE CARIBBEAN...BUOY AND ASCAT DATA ARE SHOWING MAINLY GENTLE TO MODERATE NE-E WINDS THROUGHOUT EXCEPT FOR GENTLE E WINDS ACROSS THE FAR NORTHERN TROPICAL N ATLC WHERE A WEAKENING COLD FRONT EXTENDS FROM 19N55W SW TO GUADELOUPE AND W AS A STATIONARY FRONT TO NEAR 17N76W. SEAS ELSEWHERE IN THE CARIBBEAN ARE IN THE 3-5 FT RANGE...EXCEPT FOR LOWER SEAS OF 2-3 FT IN THE FAR EASTERN CARIBBEAN. SEAS IN THE TROPICAL N ATLC ARE IN THE 5-6 FT RANGE PER CURRENT BUOY DATA AND RECENT ALTIMETER DATA. THESE SEAS WILL REMAIN IN THAT SIMILAR RANGE DURING THE PERIOD. ...SW N ATLANTIC S OF 31N W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. 12Z TAFB-NWPS USED FOR WAVE HEIGHTS. HIGH CONFIDENCE. 12Z SYNOPTIC ANALYSIS SHOWS A 1021 MB HIGH CENTERED E OF THE DISCUSSION AREA NEAR 30N59W EXTENDING A RIDGE AXIS W-SW TO 27N65W TO THE SOUTHERN FLORIDA PENINSULA NEAR 25N80W. TO THE NORTH OF THIS RIDGE AXIS...A SWIFT MOVING COLD FRONT EXTENDS FROM 31N74W TO CAPE CANAVERAL. AN EARLIER MORNING ASCAT PASS INDICATED 20 KT WINDS REMAINING GENERALLY N OF 30N E OF THE FRONT WITH MODERATE TO FRESH NW WINDS W OF THE FRONT. BUOYS AND A FEW SHIP OBS SHOW SEAS IN THE RANGE OF 4-5 FT E OF THE BAHAMAS...EXCEPT FOR 5-7 FT SEAS IN NW SWELLS N OF 29N E OF 79W IN THE VICINITY OF THE FRONT. LOWER SEAS OF 2-3 FT ARE SEEN ELSEWHERE. THE AFOREMENTIONED HIGH PRES WILL WEAKEN WITH THE PASSAGE OF ANOTHER COLD FRONT ALREADY MOVING ACROSS THE FAR NW PORTION. WINDS ASSOCIATED WITH THE COLD FRONT ARE FORECAST TO QUICKLY DIMINISH THROUGH FRI AS THE FRONT SWEEPS SEWD ACROSS THE FORECAST WATERS. HIGH PRES WILL ONCE AGAIN BUILD ACROSS THE BASIN IN THE WAKE OF THIS NEXT FRONT INTO SAT NIGHT...BUT SHIFT EASTWARD THROUGH SUN IN RESPONSE TO ANOTHER COLD FRONT THAT MOVES INTO THE FAR NW CORNER EARLY SUN. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 HUFFMAN. NATIONAL HURRICANE CENTER.