000 AGXX40 KNHC 181808 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 108 PM EST WED FEB 18 2015 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/ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST WHICH WAS A NAM BLEND. TAFB NWPS USED FOR WAVE PARAMETERS. MEDIUM CONFIDENCE. A COLD FRONT CURRENTLY EXTENDING FROM SW FL TO THE YUCATAN PENINSULA WILL MOVE SE OF THE GULF OF MEXICO LATE THIS AFTERNOON. THE SMALL AREA OF MINIMUM GALE CONDITIONS OVER THE SW GULF THIS MORNING HAVE RECENTLY DIMINISHED. INLAND OBS INDICATE THAT THE EXPECTED RE-ENFORCING COLD AIR IS JUST ABOUT TO PLUNGE INTO NE GULF WATERS AND IS EXPECTED TO QUICKLY SPREAD SE REACHING THE FL STRAITS THIS EVENING. THIS SECONDARY SURGE WILL MAINTAIN NW-N 20-25 KT FLOW ACROSS THE E GULF THROUGH THU EVENING. BY THEN A N-S POST-FRONTAL RIDGE WILL HAVE SET UP ACROSS THE CENTRAL GULF WITH SE-S 20-25 KT RETURN FLOW DEVELOPING OVER THE NW WATERS ON THU NIGHT. THE GRADIENT WILL CONTINUE TO TIGHTEN ON FRI WITH THESE E-SE 20-25 KT CONDITIONS SPREADING E ACROSS THE ENTIRE GULF...THEN FURTHER INCREASING TO 25-30 KT BRIEFLY OVER THE N-CENTRAL WATERS ON FRI NIGHT. THE GRADIENT WILL RELAX THROUGHOUT THE DAY ON SAT WITH SE 10-15 KT FLOW FORECAST ACROSS THE NORTHERN GULF...AND E-SE 15-20 KT FLOW ACROSS THE SOUTHERN GULF WATERS. A WEAK COLD FRONT EXPECTED TO NEARLY STALL OVER THE NW WATERS MIDDAY SUN WITH ONLY NE 5-10 KT CONDITIONS W OF THE BOUNDARY...AND SE 10-15 KT FLOW ELSEWHERE. A RE-ENFORCING SURGE WILL PUSH THE FRONT E BY SUN NIGHT WITH NE 10- 15 KT WINDS W OF THE FRONT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS/ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST. TAFB NWPS USED FOR WAVE PARAMETERS. MEDIUM- HIGH CONFIDENCE. A COLD FRONT WILL MOVE INTO THE NW TODAY CARIBBEAN TONIGHT ACCOMPANIED BY NORTHERLY POST-FRONTAL 20-25 KT WINDS WHICH WILL SPREAD S OVER THE ENTIRE NW CARIBBEAN BY MIDDAY THU. GUIDANCE NOW HINTING AT AN EMBEDDED SWATH OF 25-30 KT NNE WINDS BETWEEN 78-84W WHICH WILL DRIVE SEA HEIGHTS TO ABOUT 13 FT NEAR 18N82W ON THU EVENING. ALTHOUGH THE GRADIENT SHOULD RELAX SOME THU NIGHT...IT SHOULD MAINTAIN NE 20-25 KT FLOW EVERYWHERE N OF 11N W OF 74W INTO FRI MORNING...WITH ANOTHER NARROW SWATH OF EMBEDDED NE 20-30 KT FLOW EXPECTED W OF A LINE FROM THE WINDWARD PASSAGE TO NEAR 15N78W FRI EVENING. MINIMAL GALE WINDS WILL DEVELOP OFF THE NW COAST OF COLOMBIA FRI NIGHT...SAT NIGHT AND SUN NIGHT. FRESH TRADES EXPECTED ACROSS THE FAR E CARIBBEAN AND TROPICAL WATERS THROUGH FRI NIGHT... THEN INCREASING A STRONG BREEZE ON SAT INTO EARLY SUN. THE GRADIENT WILL RELAX CONSIDERABLY ACROSS THE ENTIRE AREA EARLY NEXT WEEK WITH ONLY NE 20-25 KT WINDS DEVELOPING OFF THE NW COAST COAST OF COLOMBIA LATE EACH NIGHT. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS/ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST. TAFB NWPS USED FOR WAVE PARAMETERS. MEDIUM CONFIDENCE. A COLD FRONT EXTENDING FROM 31N73W TO SE FL WILL RECEIVE A RE- ENFORCING NW BLAST WHICH WILL INCREASE THE POST-FRONTAL WNW WINDS TO MINIMAL GALE FORCE N OF 30N W OF THE FRONT BRIEFLY TONIGHT...WITH 30 KT NW WINDS REACHING AS FAR S AS THE NORTHERN PORTION OF THE BAHAMA CHANNEL. THE FRONT WILL PASS BERMUDA AND THE WINDWARD PASSAGE ON THU...THEN STALL AND DISSIPATE ACROSS THE TROPICAL WATERS N OF HISPANIOLA ON FRI. SOUTHWESTERLY 20-25 KT WINDS ARE EXPECTED N OF 28N E OF THE FRONT TO 55W THROUGH EARLY FRI. BY THEN THE GRADIENT WILL HAVE RELAXED AROUND A RIDGE EXTENDING W TO E ALONG 27N WITH GENERALLY NW-N-NE 15-20 KT FLOW EVERYWHERE W OF THE FRONT. THE GRADIENT WILL TIGHTEN S OF THE RIDGE ON FRI NIGHT INCREASING THE NE FLOW TO 20-25 KT...WITH THESE CONDITIONS SPREADING N ACROSS THE DISCUSSION WATERS S OF 28N W OF 65W BY MIDDAY SAT. THE GRADIENT WILL RELAX ON SUN AS THE RIDGE RE-ORIENTATES FROM 31N72W TO PORT CANAVERAL BY SUN EVENING. THE RIDGE WILL SHIFT A LITTLE S ON SUN NIGHT ALLOWING A COLD FRONT TO MOVE INTO THE NW WATERS ACCOMPANIED BY A 10-15 KT SW-W-NW WIND SHIFT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ031...CARIBBEAN FROM 11N TO 15N BETWEEN 72W AND 80W INCLUDING COLOMBIA BASIN... GALE CONDITIONS POSSIBLE FRI NIGHT. GALE CONDITIONS POSSIBLE SAT NIGHT. GALE CONDITIONS POSSIBLE SUN NIGHT. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ111...ATLANTIC FROM 27N TO 31N W OF 77W... GALE WARNING TONIGHT. .AMZ113...ATLANTIC FROM 27N TO 31N BETWEEN 70W AND 77W... GALE WARNING TONIGHT. $$ *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 NELSON. NATIONAL HURRICANE CENTER.