000 AGXX40 KNHC 201946 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 246 PM EST SAT DEC 20 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: GFS A COLD FRONTAL BOUNDARY PERSISTS SOMEWHAT DIAGONALLY ACROSS THE GULF TODAY...WITH WEAK LOW PRES ALONG FRONT S OF MOBILE BAY...AND STATIONARY FRONT EXTENDING GENERALLY E ALONG 29N AND INTO N FLORIDA...WHILE WEAKENING COLD FRONT EXTENDS FROM LOW SW TO CABO ROJO NEAR 21.5N97.5W. SW PORTION OF FRONT BECOMING ILL DEFINED BUT WITH BROKEN TO OVC LOW CLOUDS AND FOG ACROSS COASTAL ZONES OF MEXICO ON BOTH SIDES OF FRONT. OVERNIGHT SCAT PASSES SHOWED NLY WINDS 20 KT BEHIND FRONT AND LIKELY FREQUENT GUSTS TO 25 KT ACROSS THE SHELF WATERS...WITH SEAS BUILDING 5-7 FT AND MAX OF 8 FT. MOST RECENT 15Z SCAT PASSES SHOWED WINDS TURNING MORE NNE BEHIND THE FRONT AND WEAK LOW HAS SHIFTED NE. MODELS UNDERFORECASTING WINDS AND SEAS BEHIND FRONT...WITH BUOY 42040 NOW AT 8 FT UNDER NELY WINDS N OF LOW. FRONT AND LOW TO MEANDER OVERNIGHT THROUGH SUN AFTERNOON BEFORE FRONTAL REMNANTS BEGIN TO DRIFT N IN ADVANCE OF NEXT FRONTAL SYSTEM TO APPROACH THE REGION...AND REMNANTS OF LOW MOVE INTO BIG BEND REGION. SLY RETURN FLOW WILL INCREASE MON NIGHT AND TUE AHEAD OF FRONT...AND SPREAD ACROSS ENTIRE BASIN BY THE TIME FRONT ENTERS TEXAS COASTAL WATERS AROUND NOONTIME ON TUE. GEFS INDICATING SMALL PROBS OF GALES IMMEDIATELY BEHIND FRONT ACROSS N MEXICAN COASTAL ZONES AND THEN MODERATE TO HIGH CHANCES BY AFTERNOON ACROSS BROAD AREA BEHIND FRONT...AND CONFIDENCE THUS HIGH ON OCCURRENCE. FRONT EXPECTED TO REACH FROM CENTRAL LA TO CABO ROJO MEXICO BY TUE EVENING...PENSACOLA TO ERN BAY OF CAMPECHE BY WED MORNING AND SE OF BASIN BY THU MORNING. GALES FORECAST BY GFS TO CONTINUE ACROSS LARGE PORTION OF BAY OF CAMPECHE THROUGH WED AFTERNOON BEFORE ENDING WED EVENING AS FRONT MOVES INTO NW CARIB. PEAK SEAS LIKELY 10-13 FT BEHIND FRONT WITH MAX AROUND 15 FT SW PORTIONS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GFS WEAK W ATLC RIDGE ALONG ABOUT 26-27N PROMOTING ONLY MODERATE TO FRESH TRADES ACROSS THE CARIB E OF 80W...WITH ZONE OF 20-25 KT WINDS THIS MORNING BETWEEN 16N AND HISPANIOLA...AND SMALL AREA OF STRONG TRADES OFF COLOMBIA...WHERE RECENT ALTIMETER PASS INDICATED 7-9 FT SEAS. HIGH TO SHIFT SLIGHTLY NW THROUGH EARLY WED AND WILL INCREASE PRES GRADIENT ACROSS BASIN...AND BRING RETURN TO NOCTURNAL MAX OF 30 KT OFF COLOMBIA STARTING TONIGHT...WITH HIGHER RES GFS PARALLEL INDICATING SMALL SPOTS TO GALE FORCE THERE SUN- MON AND TUE NIGHT. OTHERWISE...INCREASED GRADIENT TO FRESHEN TRADES ACROSS ENTIRE CENTRAL PORTIONS OF BASIN TONIGHT THROUGH EARLY WED...WHILE MODERATE E TO SE FLOW PREVAILS ACROSS NW PART AND INCREASES TUE AS FRONT APPROACHES NW GULF OF MEXICO. SIMILAR TREND IN TRADES EXPECTED ACROSS TROPICAL N ATLC AS CENTRAL CARIB...WITH TRADES 20 KT BY SUN NIGHT GENERALLY S OF 13N...WHERE SEAS WILL BUILD TO 8 FT. ...SW N ATLANTIC S OF 31N W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS WEAK RIDGE NEARLY E TO W ALONG 26-27N WITH STALLED AND WEAKENING FRONTAL BOUNDARY ALONG ALMOST 30N AND FRONTAL WAVE ACROSS NW PORTIONS. 15-20 KT TRADES CURRENTLY S OF 24N. FRONT TO MEANDER ACROSS NW PART THROUGH SUN THEN BEGIN TO LIFT N AS WARM FRONT AND OUT OF AREA SUN NIGHT...BECOMING STATIONARY OFFSHORE OF CAROLINAS THROUGH LATE MON. SOUTHERLY WINDS WILL INCREASE ACROSS THE NW WATERS TUE NIGHT AHEAD OF THE STRONG COLD FRONT FORECAST TO MOVE ACROSS THE GULF OF MEXICO. GUIDANCE SUGGESTS SOUTH WINDS IN THE 20-25 KT RANGE AND BUILDING SEAS TO 7-9 FT...INCREASING TO 25-30 KT BY WED MORNING ACROSS ZONE AMZ111...AND MAY REACH MINIMAL GALE WARNING FORCE JUST AHEAD OF THE FRONT THAT IS FORECAST TO ENTER THE SW N ATLC LATE WED. THE FRONT WILL EXTEND FROM 31N75W TO CENTRAL CUBA WED NIGHT. FRESH TO STRONG WINDS AND BUILDING SEAS TO 10 FT ARE EXPECTED BEHIND THE FRONT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... .GMZ017...W CENTRAL GULF FROM 22N TO 26N W OF 94W... GALE CONDITIONS POSSIBLE TUE NIGHT. .GMZ023...SW GULF S OF 22N W OF 94W... GALE CONDITIONS POSSIBLE TUE NIGHT INTO WED. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 STRIPLING. NATIONAL HURRICANE CENTER.