000 AGXX40 KNHC 061843 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 243 PM EDT WED APR 6 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 CONSENSUS NEXT FRONTAL BOUNDARY IS NOW OVER SE TEXAS AND APPROACHING NW WATERS. RETURN FLOW ACROSS THE ENTIRE BASIN EARLIER TODAY HAS BEGUN TO DIMINISH NW PORTIONS AHEAD OF THE FRONT...WHILE FRESH SE WINDS ACROSS NE PORTIONS HAVE KICKED UP SEAS TO 4-6 FT PER RECENT BUOY OBS THERE. FRONT TO MOVE INTO NW GULF THIS EVENING AND REACH FROM FL BIG BEND TO JUST S OF BRO BY 12Z THU THEN WASH OUT ACROSS SE PORTIONS AND FL STRAITS FRI MORNING. WEAK HIGH PRES BEHIND FRONT WILL SETTLE ACROSS NW GULF THU AND FRI BEFORE ANOTHER FRONT IN E-W ALIGNMENT SINKS ACROSS N GULF FRI...THEN SHIFTS SE ACROSS ERN PORTIONS THROUGH THE WEEKEND. MODELS IN GOOD AGREEMENT THROUGH FRI BUT THEN BEGIN TO SHOW MODEST DIFFERENCES IN FRONTAL POSITION ACROSS THE SE GULF OVER THE WEEKEND...WITH GFS FASTER AND FARTHER SE THEN ENSEMBLES AND EURO MODELS...AND HAVE ADJUSTED TOWARD ECMWF. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS VERY WEAK PRES GRADIENT ACROSS MOST OF THE BASIN PAST COUPLE OF DAYS HAS PRODUCED A DOWNWARD TREND IN WAVE HEIGHTS...WITH FRESH TO STRONG TRADES CONFINED ONLY TO COLOMBIAN BASIN...AND FRESH NE WINDS ACROSS NW PORTIONS AND THROUGH WINDWARD PASSAGE...BEHIND WASHED OUT FRONTAL BOUNDARY IN WINDWARD PASSAGE. ANOMALOUS SEAS ONLY 3 FT BEING REPORTED BY 42058 AND 42059. HIGH PRES BEHIND THIS FRONT ALONG THE MID ATLC COASTS AND WILL SHIFT NE TONIGHT AND THU AND NOT ALLOW FOR MUCH INCREASE IN PRES GRADIENT ACROSS THE BASIN THROUGH SAT BEFORE ONE OF SERIES OF WEAK SWEEPING FRONTS MOVES ACROSS NW PORTIONS OVER THE WEEKEND...AND HIGH BEGINS TO BUILD S AND SE ACROSS W HALF OF BASIN LATE SAT TO INCREASE WINDS AND BRING A RETURN TO NOCTURNAL MAX NEAR GALES OFF OF COLOMBIA SAT NIGHT. 12Z RUN OF GFS STILL LOOKS FASTER AND SLIGHTLY FARTHER SE THAN OTHER GUIDANCE WITH THIS FRONT AND WAS PRODUCING STRONGER WINDS THAN 00Z RUN OF ECMWF. WILL WAIT FOR ECMWF TO COME IN BEFORE MAKING ANY ADJUSTMENTS TO THIS STRONG NE FLOW SAT AND SUN BUT LOOKS REASONABLE ATTM. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS COLD FRONT SLOWING AND IS ABOUT TO STALL FROM WINDWARD PASSAGE TO 23.5N65W WITH PRE FRONTAL TROUGH STILL TO SE OF FRONT. SECOND DRY FRONT TRANSITIONING TO SHEARLINE STRUCTURE AND STALLING FROM UPPER FL KEYS TO NEAR 28N60W...WHERE IT WILL NEARLY MERGE WITH PRECEDING FRONT. STRONG HIGH PRES BEHIND BOTH BOUNDARIES HAVE PRODUCE FRESH TO STRONG NE WINDS BEHIND SECOND FRONT OVERNIGHT AND THIS MORNING AND ARE PRODUCING BUILDING WIND SEA NW OF BOTH BOUNDARIES. A 1340Z ALTIMETER PASS THROUGH THE FL STRAITS BETWEEN SE FL AND BAHAMAS CLEARLY SHOWED SEAS 7.5-9.5 FT INVOF FL CURRENT. ELSEWHERE...NLY SWELL GENERATED RECENTLY ACROSS NW ATLC AND MOVING INTO N PORTIONS OF DISCUSSION AREA IS UNDERFORECAST SLIGHTLY BY ECWAVE AND 3-4 FT BY WW3 PER REGIONAL BUOY OBS. PREVIOUS FORECAST USED TAFB NWPS WHICH INTRODUCED AN EVEN LOWER BIAS IN ATLC SWH FORECASTS AND HAVE HAD TO BUILD DATA BASE FROM NEW AND BLENDED LARGE PERCENTAGE OF ECWAVE FOR THIS EVENT. PERSISTENT UPPER TROUGHING ACROSS W ATLC AND ERN U.S. WILL SUPPORT SERIES OF WEAK FRONTAL BOUNDARIES SWEEPING ACROSS THE AREA NEXT SEVERAL DAYS...ALL GENERALLY NOT MOVING DEEPER SE THAN WINDWARD PASSAGE BEFORE SUPPORTING ENERGY LIFTS OUT TO NE AND LEAVES FRONTAL REMNANTS BECOMING ENE TO WSW ALIGNED ALONG ABOUT 23-24N THROUGH SE BAHAMAS AND ERN CUBA THROUGH EARLY NEXT WEEK. SUPPORTING LOW CENTERS TO DEVELOP ACROSS NE U.S. AND NW ATLC AND COMBINE WITH ATLC HIGH TO KEEP FRESH TO STRONG SLY FLOW AHEAD OF FRONT CONFINED TO N PORTIONS N OF 29N...AND NWLY FLOW BEHIND FRONTS N OF 29-30N THROUGH EARLY SUN. HIGH BEHIND WEEKEND FRONTAL SYSTEM SNAGGING THROUGH WINDWARD PASSAGE TO PRODUCE STRONG NE WINDS NW OF FRONT AND THROUGH BAHAMAS TO SE FL SUN THROUGH MON...WITH SEAS BUILDING 8-11 FT...AT LEAST...E OF BAHAMAS. GFS STILL TRENDING FASTER AND FARTHER SE WITH BOUNDARIES THAN OTHER GLOBAL MODELS AND ENSEMBLES...AND HAVE LEANED TOWARD ECMWF. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 STRIPLING. NATIONAL HURRICANE CENTER.