000 AGXX40 KNHC 201933 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1244 PM EDT MON APR 20 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 BLENDED WITH PREVIOUS OFFICIAL FOR WINDS. TAFB NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. HIGH CONFIDENCE. ORGANIZED CONVECTION WILL MOVE EASTWARD ACROSS THE EASTERN GULF THROUGH TONIGHT AHEAD OF A FAST MOVING COLD FRONT. THE MODELS AGREE ON RACING THE COLD FRONT FROM ITS 1200 UTC LOCATION STRETCHED FROM SE LOUISIANA TO CORPUS CHRISTI...REACHING FROM SARASOTA TO NE MEXICO NEAR 25N98W TUE MORNING AND DISSIPATING ALONG 25N WED AS SE RETURN FLOW BUILDS OVER THE GULF. A RIDGE WILL SET UP FROM THE SE GULF TO THE NW GULF THU THROUGH SAT. WINDS AND SEAS ARE NOT EXPECTED TO REACH ADVISORY CRITERIA AT ANY POINT IN THE FORECAST PERIOD THAT ENDS FRI NIGHT. THE GFS AND NWPS FORECASTS LOOK REASONABLE FOR ADJUSTING THE OFFICIAL FORECAST. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL FOR WINDS. TAFB NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES IN THE CARIBBEAN. EC WAVE BLENDED WITH PREVIOUS OFFICIAL IN THE ATLC. HIGH CONFIDENCE. ATLC RIDGING N OF THE AREA...COMBINED WITH LOWER PRES OVER NW COLOMBIA...WILL SUPPORT 20-25 KT NE WINDS ALONG COAST OF COLOMBIA THROUGH THE PERIOD...WITH SOME VARIATION IN THE EXTENT OF THESE WINDS BASED ON THE STRENGTH OF THE SUBTROPICAL RIDGE TO THE N UNDER A PROGRESSIVE PATTERN. SIMILARLY...A FRESH TO STRONG E-SE BREEZE IS EXPECTED OFFSHORE OF THE GULF OF HONDURAS EACH NIGHT...WITH SEAS BUILDING TO 8 FT. ELSEWHERE...MODERATE TO FRESH TRADES ARE EXPECTED. NE SWELL WILL CONTINUE SUBSIDE OVER THE TROPICAL ATLC WATERS THROUGH TUE. THE EC WAVE COMPARES WELL WITH ALTIMETER PASSES WELL E OF THE ISLANDS BETWEEN 40W-53W SHOWING 8-11 FT SEAS WHILE THE MWW3 IS 2-3 FT TOO LOW AND THE NWPS IS ABOUT 3-4 FT TOO LOW. ATLC SWELL IN THE NWPS IS STILL CATCHING UP FROM A COLD START THAT WAS PERFORMED SATURDAY. THE EC WAVE WAS USED TO ADJUST SEAS IN THE ATLC. THE NWPS LOOKS REASONABLE IN THE CLOSED CARIBBEAN BASIN. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL FOR WINDS. MWW3 AND TAFB NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. MEDIUM CONFIDENCE. THE LATEST GFS AND ECMWF MODELS HAVE COME INTO BETTER AGREEMENT WITH THE PROGRESSIVE PATTERN OVER THE WESTERN AND CENTRAL ATLC...CARRYING A COLD FRONT IN TO NW WATERS TONIGHT AND STRETCHING IT FROM BERMUDA TO S FLORIDA TUE NIGHT. ANOTHER COLD FRONT IS FORECAST TO REACH NW WATERS THU. THE GFS IS FASTER THAN THE ECMWF WITH THIS FRONT AND MATCHES BETTER WITH THE EC ENS AND GEFS MEANS THU AND FRI WITH THE EVOLUTION OF THE PATTERN N OF THE AREA WHICH IMPACTS THE TIMING OF THE FRONT. THE GFS LOOKS REASONABLE FOR ADJUSTING THE WINDS. WITH SWELL LESS OF A CONCERN OVER THE SW N ATLC...THE NWPS LOOKS MORE REASONABLE HERE THAN IN THE TROPICAL N ATLC...BUT IT IS STILL CATCHING UP FROM THE COLD START OVER THE WEEKEND AND RUNNING 1-2 FT LOWER THAN THE MWW3 AND OBSERVATIONS INITIALLY. THE MMW3 WAS PRIMARILY USED TO ADJUST THE SEAS...WITH THE NWPS USED MOSTLY NEAR THE BAHAMAS WHERE BATHYMETRY IS MORE OF A FACTOR. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.