000 AGXX40 KNHC 181813 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 213 PM EDT FRI MAR 18 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 BLENDED WITH PREVIOUS OFFICIAL WIND FORECAST. 12Z NWPS BLENDED WITH OFFICIAL WAVE FORECAST. HIGH CONFIDENCE THROUGH FRI THEN MEDIUM CONFIDENCE. THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THE MESSY EVOLUTION OF THE LOW PRES SYSTEM AND MERGING FRONTAL BOUNDARIES IN THE GULF OF MEXICO OVER THE WEEKEND. THE BIGGEST FORECAST CHALLENGE IS WHERE AND WHEN TO CARRY GALE FORCE WINDS. THE 00Z ECMWF AND 12Z GFS AGREE ON GALE IN THE FAR SW GULF. 00Z ECMWF SHOWS GALES 18Z SUN AND 00Z MON WHILE THE 12Z GFS CARRIES GALES AT 12Z AND 18Z SUN. BLENDING WITH THE PREVIOUS FORECAST LED TO GALE WINDS PERSISTING THROUGHOUT THIS TIME PERIOD...AND THE LATEST SREF SHOWS AT LEAST A 40 PERCENT CHANCE OF GALES DURING THAT TIME. THE TERRAIN HERE IS NOT AS WELL RESOLVED BY THE GLOBAL MODELS AS IT IS BY THE REGIONAL MODELS THAT MAKE UP THE SREF. BASED ON THIS...WILL NOT MAKE FURTHER ADJUSTMENTS TO THE GALE WINDS PRODUCED BY THE MODEL/OFFICIAL BLEND. THE SREF ALSO SHOWS UP TO A 20 PERCENT CHANCE OF GALES OFFSHORE JUST N OF TAMPICO...BUT THE MODEL BLEND KEPT WINDS JUST BELOW GALE FORCE HERE. AGAIN...WILL KEEP WITH THE ORIGINAL MODEL BLEND. THIS WIND FORECAST WAS ADOPTED FOR THE 12Z NWPS RUN...SO IT WAS USED TO ADJUST THE SEAS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12Z GFS BLENDED WITH THE OFFICIAL FORECAST THROUGH FRI THEN A GLOBAL MODEL BLEND BLENDED WITH PREVIOUS OFFICIAL WIND FORECAST. 12Z NWPS BLENDED WITH OFFICIAL WAVE FORECAST. HIGH CONFIDENCE. THE 12Z GFS WAS THE BEST INITIALIZED WITH THE FRESH E-SE WINDS N OF HONDURAS AND THE FRESH TO STRONG NE-E WINDS NEAR THE CENTRAL COLOMBIAN COAST THIS MORNING. IT GENERALLY PERFORMS BETTER WITH THE TERRAIN INFLUENCED WINDS IN THESE AREAS BY SHOWING STRONGER WINDS...SO IT WAS RELIED ON MORE HEAVILY THROUGH FRI. THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THE COLD FRONT MOVING THROUGH THE YUCATAN CHANNEL AND INTO THE NW CARIBBEAN SUN NIGHT. BOTH THE GFS AND ECMWF SHOW WINDS INCREASING TO 25 KT IN THE YUCATAN CHANNEL AT 06Z MON. THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE FRONTAL TIMING...BUT THE ECMWF GENERALLY CARRIES A LARGER AREA OF FRESH TO STRONG N-NE WINDS BEHIND THE FRONT MON THAN THE GFS. A BLEND WAS USED TO ADJUST THE GRIDS. THIS WIND FORECAST WAS ADOPTED FOR THE 12Z NWPS RUN...SO IT WAS USED TO ADJUST THE SEAS. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL BLEND BLENDED WITH PREVIOUS OFFICIAL WIND FORECAST. 12Z NWPS BLENDED WITH OFFICIAL WAVE FORECAST. MEDIUM CONFIDENCE. THERE IS SOME UNCERTAINTY WIT THE FORECAST OVER THE WEEKEND AS LOW PRES DEVELOPS IN THE GULF OF MEXICO AND MOVES NE INTO THE ATLC. THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THE EVOLUTION OF THE LOW AND TIMING OF THE COLD FRONT...BUT THE 12Z GFS REMAINS SLIGHTLY FASTER THAN THE 00Z ECMWF HERE. THEY BOTH AGREE ON CARRYING 30 KT WINDS AHEAD OF THE FRONT OVER NE WATERS BY 18Z MON...BUT THE 00Z ECMWF IS WEAKER WITH THE WINDS BEHIND THE FRONT OVERNIGHT SUN NIGHT AND EARLY MON THAN THE 12Z GFS WHICH SHOWS 30 KT. A BLEND OF THESE MODELS WITH THE OFFICIAL FORECAST SEEMS BEST. THIS WIND FORECAST WAS ADOPTED FOR THE 12Z NWPS RUN...SO IT WAS USED TO ADJUST THE SEAS. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... .GMZ023...SW GULF S OF 22N W OF 94W... GALE WARNING SUN. GALE CONDITIONS POSSIBLE SUN INTO SUN NIGHT. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.