000 AGXX40 KNHC 031813 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 213 PM EDT SUN APR 3 2016 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: GLOBAL MODEL BLEND WITH PREVIOUS OFFICIAL WIND FORECAST. NWPS BLENDED WITH PREVIOUS OFFICIAL WAVE FORECAST. HIGH CONFIDENCE. THE 00Z/03 ECMWF CARRIES A FRESH TO STRONG N-NE BREEZE NEAR THE YUCATAN PENINSULA BEHIND THE COLD FRONT STRETCHED FROM THE STRAITS OF FLORIDA TO CANCUN MEXICO. THIS MATCHES OBSERVATIONS BETTER THAN THE WEAKER 12Z GFS AND IS IN BETTER AGREEMENT WITH THE 12Z UKMET. IN TURN...THE 00Z/03 EC WAVE CARRIES HIGHER SIGNIFICANT WAVE HEIGHTS AND HANGS ONTO THE SWELL A BIT LONGER THAN THE 12Z MWW3. THE EC WAVE MATCHES THE 3 ALTIMETER PASSES BETWEEN 1130Z- 1430Z IN THE GULF OF MEXICO BETTER THAN THE LOWER VALUES OF THE MWW3. THE EC WAVE HAS A BETTER TRACK RECORD UNDER SIMILAR CONDITIONS...SO IT WAS RELIED ON FOR ADJUSTING THE GRIDS THROUGH MON. STARTING TONIGHT...HIGH PRES DOMINATES THE GULF. MODEL DIFFERENCES ARE RATHER SLIGHT UNTIL WED NIGHT WHEN A NEW COLD FRONT APPROACHES THE GULF. THE ECMWF IS SLIGHTLY FASTER AND STRONGER THAN THE GFS WITH THE FRONT. THE ECMWF WRAPS UP A SURFACE WAVE OVER THE SOUTHERN APPALACHIANS AND MID ATLC REGION ON THU. THE GFS IS MUCH WEAKER WITH A WAVE HERE ALONG THE COLD FRONT...BUT THE EC ENS MEAN AND...TO A LESSER EXTENT...THE GEFS MEAN SIDE WITH THE ECMWF SOLUTION WHICH IS FASTER TO DRAG THE COLD FRONT INTO THE GULF. THE BLEND FROM WED NIGHT ONWARD SIDED MORE WITH THE ECMWF TO ACKNOWLEDGE THE ENS MEAN PREFERENCE. THE 12Z NWPS RUN TOOK THIS INTO ACCOUNT. ITS SOLUTION WAS USED TO ADJUST THE SEAS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST 12Z GFS BLENDED WITH PREVIOUS OFFICIAL WIND FORECAST THROUGH WED THEN A GLOBAL MODEL BLEND BLENDED WITH THE PREVIOUS OFFICIAL FORECAST. NWPS BLENDED WITH PREVIOUS OFFICIAL FORECAST FOR WAVES. HIGH CONFIDENCE THROUGH WED THEN MEDIUM CONFIDENCE. THE GRADIENT BETWEEN ATLC HIGH PRESSURE AND BROAD LOW PRESSURE OVER NORTHERN COLOMBIA WILL PRODUCE STRONG NE-E WINDS WITHIN 90 NM OF THE NW COAST OF COLOMBIA BEGINNING IN THE LATE AFTERNOONS...AND CONTINUING INTO THE EARLY MORNING HOURS THROUGH THU MORNING. A WEAK COLD FRONT IS CURRENTLY MOVING SE THROUGH THE YUCATAN CHANNEL. THE FRONT WILL SLOWLY MOVE E ACROSS THE NW CARIBBEAN ON MON AND TUE BEFORE STALLING ACROSS THE SOUTHERN APPROACH TO THE WINDWARD PASSAGE WED AND DISSIPATING THU. THE GFS IS IN LINE WITH THE FAVORED FORECAST FOR THE GENERAL PATTERN TO THE N THROUGH WED WHICH IMPACTS THE STRENGTH OF THE PRES GRADIENT ACROSS THE CARIBBEAN. THE GFS IS GENERALLY BETTER WITH ITS STRONGER TOPOGRAPHICALLY ENHANCED WINDS OFF COLOMBIA WHEN THE LARGE-SCALE PATTERN TO THE N IS WELL FORECAST. THE GFS WILL BE USED TO ADJUST THE GRIDS HERE AS WELL THROUGH WED. AS STATED IN THE GULF OF MEXICO SECTION...THE ECMWF BECOMES THE FAVORED SOLUTION FOR ADJUSTING THE FORECAST WITH THE COLD FRONT EXPECTED TO MOVE INTO THE NORTHERN GULF WED NIGHT. THIS CALLS FOR A FASTER BREAKDOWN OF THE RIDGING N OF THE AREA WHICH DIMINISHES THE WINDS ALONG THE COAST OF COLOMBIA LATE THU BELOW A FRESH TO STRONG BREEZE. THE 12Z NWPS ADOPTED THIS PREFERRED WIND FIELD AND SEEMED REASONABLE FOR ADJUSTING THE SEAS. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL WIND FORECAST THROUGH WED. GLOBAL MODEL BLEND WITH PREVIOUS OFFICIAL WED NIGHT ONWARD. NWPS BLENDED WITH PREVIOUS OFFICIAL WAVE FORECAST. HIGH CONFIDENCE THROUGH WED THEN MEDIUM CONFIDENCE. THE 00Z/03 ECMWF AND 12Z GFS ARE IN GOOD AGREEMENT WITH THE EXTENT OF THE FRESH TO STRONG SW WINDS AHEAD OF THE COLD FRONT OVER NE WATERS INITIALLY. THESE MODELS ARE IN REMARKABLY GOOD AGREEMENT WITH THE FRONT AS A WAVE DEVELOPS ALONG IT AND MOVES NORTHEASTWARD THROUGH THE SW N ATLC MON THROUGH TUE. THEY ARE ALSO IN GOOD AGREEMENT WITH THE STRENGTH AND TIMING OF THE REINFORCING COLD FRONT MOVING INTO NW WATERS LATE TUE INTO WED. THE GFS SEEMED FINE FOR ADJUSTING THE WIND GRIDS THROUGH WED. AS DISCUSSED IN THE GULF OF MEXICO SECTION...THE ECMWF CARRIES A MORE WRAPPED UP LOW PRES SYSTEM THROUGH THE MID ATLC THU INTO FRI THAN THE GFS SOLUTION. THE EC ENS AND GEFS MEANS SIDE WITH THE ECMWF SOLUTION...SO IT WAS USED TO ADJUST THE GRIDS. THE ECMWF BECOMES SLOWER AND STRONGER THAN THE WEAKER AND MORE PROGRESSIVE GFS IN THE SW N ATLC THU AND FRI. THE 12Z NWPS ADOPTED THIS PREFERRED WIND FIELD AND WAS USED TO ADJUST THE 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 SCHAUER. NATIONAL HURRICANE CENTER.