000 AGXX40 KNHC 041920 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 220 PM EST THU DEC 4 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: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. LATEST TAFB-NWPS USED TO ADJUST WAVE PARAMETERS. HIGH CONFIDENCE. STATIONARY FRONT ALONG THE GULF COAST IS WEAKENING WITH HIGH PRESSURE BRIDGING THROUGH THE FRONT. WEAK SURFACE TROUGH WAS NOTED OVER THE FAR W GULF. LATEST SATELLITE DERIVED WINDS AND SEAS ALONG WITH SHIP...BUOY...AND CMAN DATA DEPICT MODERATE TO FRESH WINDS OVER THE SE GULF...AND LIGHT TO MODERATE WINDS OVER THE REMAINDER OF THE GULF WATERS. BUOY AND ALTIMETER DATA INDICATED SEAS ARE IN THE 4-5 FT RANGE OVER THE SE GULF AND 2-4 FT OVER THE REMAINDER OF THE GULF WATERS. THE SURFACE TROUGH OVER THE W GULF SHOULD DISSIPATE TONIGHT WHILE HIGH PRESSURE PREVAILS OVER THE REMAINDER OF THE AREA INTO SAT. A COLD FRONT WILL MOVE INTO THE FAR NORTHERN WATERS SAT EVENING BUT WITH LITTLE PROGRESS INTO THE GULF WATERS BEFORE IT STALLS AND BECOMES DIFFUSE ON SUN. SUBTLE MODEL DIFFERENCES NOTED WITH THE TIMING OF THE FRONT...WITH THE UKMET THE FASTEST AND MOST ROBUST OF THE MODELS IN TERMS OF WINDS BEHIND THE FRONT. THE GFS/ECMWF IS THE PREFERRED SOLUTION. HIGH PRES BUILDS IN MON AND TUE BEHIND THE FRONT WITH LIGHT TO MODERATE NE WINDS AND SEAS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST THROUGH FRI THEN BLEND OF GFS/ECMWF/OFFICIAL AFTERWARDS. LATEST TAFB- NWPS USED TO ADJUST WAVE PARAMETERS. HIGH CONFIDENCE. LATEST SATELLITE DERIVED WINDS AND SEAS ALONG WITH SHIP...BUOY... AND ALTIMETER DATA DEPICT FRESH TO LOCALLY STRONG TRADES OVER THE SW CARIBBEAN WATERS...MODERATE TO FRESH WINDS OVER THE REMAINDER OF THE CENTRAL AND WESTERN CARIBBEAN...GENTLE TO MODERATE WINDS OVER THE EASTERN CARIBBEAN...AND GENTLE WINDS OVER THE TROPICAL N ATLC WATERS. SEAS ARE IN THE 8-10 FT RANGE OVER THE SW CARIBBEAN...5-7 FT OVER THE REMAINDER OF THE CENTRAL AND WESTERN CARIBBEAN...3-5 FT OVER THE EASTERN CARIBBEAN...AND 5-6 FT OVER THE TROPICAL N ATLC WATERS. WINDS AND SEAS OVER THE CENTRAL CARIBBEAN WILL CONTINUE TO DECREASE THROUGH TONIGHT. BROAD TROUGHING OVER THE WEST-CENTRAL ATLC WATERS WILL KEEP THE PRESSURE GRADIENT WEAK OVER MUCH OF THE CARIBBEAN...EXCEPT FOR PORTIONS OF THE NW CARIBBEAN WHERE A LOCALLY TIGHTER GRADIENT BETWEEN A RIDGE OF HIGH PRESSURE OVER THE GULF AND THE SURFACE TROUGH WILL FRESHEN WINDS THROUGH THE FIRST HALF OF THE WEEKEND. WITH COLD FRONTS SWEEPING ACROSS THE SW N ATLC SUN THROUGH TUE SUB-NORMAL TRADES ARE EXPECTED WITH SEAS OF 2-4 FT OVER MOST AREAS. ...SW N ATLANTIC S OF 31N W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. LATEST TAFB-NWPS USED TO ADJUST WAVE PARAMETERS. HIGH CONFIDENCE. A BROAD SURFACE TROUGH PREVAILS E OF THE SW N ATLC FORECAST AREA AND EXTENDS INTO THE FAR NW TROPICAL N ATLC AND NE CARIBBEAN. LATEST SATELLITE DERIVED WINDS...ALTIMETER DATA...SHIP...BUOY...AND CMAN DATA DEPICT MODERATE TO LOCALLY FRESH WINDS W OF 70W AND LIGHT TO MODERATE WINDS E OF 70W. SEAS AREA IN THE 7-9 FT RANGE OVER THE EASTERN HALF OF THE FORECAST AREA...5-7 FT OVER THE WESTERN PART OF THE FORECAST AREA OUTSIDE THE BAHAMAS..AND 2-4 FT W OF THE BAHAMA BANK. LOW PRESSURE IS EXPECTED TO FORM ALONG THE TROUGH WELL E OF THE AREA ON FRI THEN MOVE N SAT AND SUN ALONG 60W. AS LOW PRES MOVES N PRES GRADIENT FRESHENS E OF THE AREA WITH RESULTANT SEAS OF 9-10 FT SPILLING INTO THE AREA E OF 70W. A COLD FRONT WILL MOVE OFF THE COAST OF THE SE UNITED STATES SAT NIGHT INTO SUN AND EXTEND TO ALONG 28N SUN AND MON. FRESH TO STRONG NORTHERLY WINDS AND BUILDING SEAS ARE EXPECTED IN THE WAKE OF THE FRONT. SIGNIFICANT NWP DIFFERENCES EXIST IN THE TREATMENT OF THIS FRONT. THE UKMET IS A FAST AND MORE ROBUST OUTLIER OF THE SUITE OF MODELS IN TERMS OF WINDS AND SEAS BEHIND THE FRONT. THE UKMET/ECMWF ARE SIMILAR IN TERMS OF THE TRAJECTORY OF THE WINDS BEHIND THE FRONT WITH MORE NORTHERLY WINDS NOTED. THE GFS IS MORE PROGRESSIVE WITH THE FRONT WITH WINDS MORE FROM THE EAST. AS A RESULT IN THE NWP DIFFERENCES...STARK CONTRASTS IN SEAS NOTED WITH THE UKMET WW FORECASTING SEAS OF 14-17 FT OVER THE FAR NW WATERS VERSUS A MORE REASONABLE 11-12 FT PER THE NWW3 ON MON. THE GFS/NWW3 IS THE PREFERRED SOLUTION. A REINFORCING FRONT MOVES OFF THE SE COAST MON NIGHT AND TUE MAINTAINING MODERATE TO STRONG WINDS AND HIGHER SEAS. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 COBB. NATIONAL HURRICANE CENTER.