000 AGXX40 KNHC 271819 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 119 PM EST SAT DEC 27 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 BLENDED WITH PREVIOUS/OFFICIAL FORECAST. LATEST MWW3 AND TAFB-NWPS USED FOR WAVE HEIGHTS. MEDIUM CONFIDENCE. THE 00Z ECMWF HAS BACKED OFF WITH THE STRENGTH OF THE WINDS BEHIND THE COLD FRONT TONIGHT THROUGH SUN...DELAYING WINDS REACHING 25 KT UNTIL 18Z SUN WHILE THE 12Z GFS SHOWS WINDS THAT STRONG AS SOON AS THE FRONT MOVES OVER THE 72 DEGREE WATERS IN THE NW GULF TONIGHT AND CONTINUES TO SHOW WINDS TO 30 KT ALONG THE COAST OF VERACRUZ SUN AFTERNOON. THE FRONT APPEARS TO BE STRONG...WITH THE OBSERVATION IN SAN ANTONIO DIPPING 15 DEGREES IN THE LAST 2 HOURS AND WINDS INCREASING FROM 5 KT AHEAD OF THE FRONT TO 20 KT BEHIND IT. THE STRONGER SOLUTION SEEMS MORE LIKELY...SO THE GFS WAS USED TO ADJUST THE FORECAST. THE GFS IS SLIGHTLY FASTER TO MOVE THE FRONT EASTWARD THROUGH THE NE GULF AS IT WEAKENS SUN NIGHT AND MON. THE MODELS HAVE HAS A HARD TIME SETTLING ON A FORECAST WITH THIS FRONT...SO CONFIDENCE IS NOT EXTREMELY HIGH. BOTH THE GFS AND ECMWF SHOW HIGH PRES BUILDING IN EARNEST BEHIND THE FRONT TUE AND WED...WITH THE GFS SLIGHTLY STRONGER WITH WINDS OVER THE N GULF WED. BY WED NIGHT...BOTH MODELS SHOW TROUGHING BUILDING OVER THE W GULF AND INCREASE WINDS TO 20-25 KT IN THE NW PORTION. THERE IS ALSO GOOD AGREEMENT ON THE DEVELOPMENT OF A SURFACE LOW ALONG THE TEXAS COAST THU. THE GFS SOLUTION IS NOT THAT FAR OFF THE ECMWF HERE...SO IT WAS USED THROUGHOUT THE FORECAST PERIOD TO ADJUST THE WINDS. THE MWW3 HAD LARGER SEAS BEHIND THE FRONT TONIGHT THROUGH MON NIGHT THAN THE NWPS AND LOOKS MORE REASONABLE COMPARED TO THE PREFERRED STRONG WIND SPEEDS OF THE GFS. BEYOND MON NIGHT...THE NWPS COMES INTO BETTER AGREEMENT WITH THE MWW3 AND WAS USED TO ADJUST THE FORECAST. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. LATEST TAFB-NWPS USED FOR WAVE HEIGHTS IN THE CARIBBEAN WITH THE MWW3 ALSO USED IN THE BLEND IN THE TROPICAL N ATLC. HIGH CONFIDENCE. BAGGY HIGH PRES OVER THE BAHAMAS HAS ALSO INCREASED THE PRES GRADIENT IN THE LEE OF CUBA AND IN THE WINDWARD PASSAGE WHERE 20-25 KT WINDS ARE CURRENTLY FOUND. WINDS IN THE LEE OF CUBA ARE EXPECTED TO DIMINISH BELOW A STRONG BREEZE LATER TODAY AS HIGH PRES ORGANIZES NE OF THE AREA WHILE WINDS IN THE WINDWARD PASSAGE WILL REMAIN A FRESH TO STRONG BREEZE THROUGH SUN MORNING. THE STRONGER...HIGHER RESOLUTION GFS WAS USED FOR THE WIND FORECAST HERE...WITH WINDS BUMPED UP A BIT AS IT HAS A LOW BIAS IN ENHANCED NE FLOW EVENTS HERE. THE NWPS SEAS WERE HIGHER THAN THE MWW3 HERE AND MORE CLOSELY MATCHED THE WINDS. AS THE HIGH MOVES E...THE AREA OF WINDS AT OR ABOVE ADVISORY CRITERIA CENTERED OVER THE CENTRAL CARIBBEAN WILL SHRINK. THE GFS SEEMS REASONABLE AND GENERALLY DOES BEST WITH THE STRONGER WINDS ALONG THE COAST OF COLOMBIA WHERE IT SHOWS 30 KT EVERY MORNING THROUGH THE PERIOD. IN THE TROPICAL N ATLC...NE SWELL HAS BROUGHT SEAS OVER 8 FT TO WATERS N OF 14N ACCORDING TO AN 1100Z ALTIMETER HAS. SEAS OVER 8 FT WILL SPREAD OVER THE ENTIRE AREA THROUGH THE WEEKEND. SEAS WILL BE SLOW TO SUBSIDE HERE. THE NWPS IS STILL SPINNING UP THE SWELL OVER THE ATLC BASIN AND APPEARS LOW WITH WAVE HEIGHTS ON DAY 1. RELIED MORE ON THE MWW3 FOR WAVES EARLY IN THE PERIOD. THE MWW3 AND NWPS ARE IN GOOD AGREEMENT ON SEAS HOVERING IN THE 7-9 FT RANGE INTO MON AND TUE AND SUBSIDING FURTHER ON WED. ...SW N ATLANTIC S OF 31N W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST THROUGH WED WITH THE ECMWF ADDED WED NIGHT AND THU. LATEST TAFB-NWPS AND MWW3 USED FOR WAVE HEIGHTS WITH THE EC WAVE ADDED WED NIGHT AND THU. MEDIUM CONFIDENCE. NE SWELL OVER 8 FT OVER WATERS E OF 70W CONTINUES TO SPREAD SW...CURRENTLY APPROACHING PUERTO RICO AND EXPECTED TO REACH THE SE BAHAMAS TONIGHT BEFORE GRADUALLY SUBSIDING SUN NIGHT THROUGH TUE. THE NWPS IS SLOWER TO ADVANCE THE SWELL THAN THE MWW3 FOR THE FIRST 24 HOURS...BUT THEN IS IN BETTER AGREEMENT WITH THE MWW3. THE MWW3 WAS RELIED ON FOR ADJUSTING SEAS FOR DAY 1. THE 12Z GFS AND 00Z ECMWF HAVE COME INTO MUCH BETTER AGREEMENT WITH THE TIMING OF THE COLD FRONT MOVING OFF THE NE FLORIDA COAST TUE...WITH BOTH MODELS EXTENDING THE FRONT FROM 31N71W TO CAPE CANAVERAL TUE EVENING AND WEAKENING THE FRONT WED. LARGER DIFFERENCES COME INTO PLAY WED NIGHT AND THU WHEN THE WHEN THE GFS BUILDS CONSIDERABLY STRONGER HIGH PRES N OF THE AREA WHERE THE ECMWF SHOWS A TROUGH AT THE SURFACE. THE GFS SHOWS A SOLID AREA OF 20 KT NE WINDS OVER N WATERS WED NIGHT WHILE THE ECMWF GENERALLY SHOWS A GENTLE BREEZE WITH MORE NORTHERLY FLOW OVER W WATERS. THE UKMET DOES NOT SHOW GOOD AGREEMENT WITH EITHER MODEL AND THE CORRESPONDING ENS MEANS LOOK LIKE WEAKER VERSIONS OF THE OPERATIONAL MODEL. A BLEND OF THE 12Z GFS AND 00Z ECMWF SEEMS BEST FOR ADJUSTING THE FORECAST FROM WED NIGHT ONWARD. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 SCHAUER. NATIONAL HURRICANE CENTER.