000 AGXX40 KNHC 151844 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 244 PM EDT SAT OCT 15 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. HIGH PRESSURE RIDGE ALONG EASTERN SEABOARD EXTENDS SSW ACROSS N GULF STATES THIS AFTERNOON. AN OLD FRONTAL ZONE SNAKES WWD THROUGH THE STRAITS OF FL TO CENTRAL GULF NEAR 23.5N91W...WHILE STLT AND RECENT ASCAT PASS INDICATE A BROAD AND WEAK LOW HAS DEVELOPED ACROSS THE SW GULF NEAR 21N92.6W WITH WEAK TROFFING EXTENDING NW TO CENTRAL MEXICAN COAST. MODERATE TO FRESH ELY WINDS PREVAIL N OF OLD FRONT/SHEARLINE WHERE SEAS ARE 4-5 FT WITH EARLIER MAX OF 6 FT ACROSS CENTRAL GULF. THIS PATTERN GENERALLY EXPECTED TO PERSIST NEXT FEW DAYS WHILE ELONGATED TROF DEVELOPS ACROSS CENTRAL BAHAMAS AND ADJACENT ATLC...AND BROAD MONSOONAL LOW LINGERS ACROSS SW-W CARIB. ANY CHANGES TO THIS WILL BE CONTINGENT ON ONE OF THESE TWO SYSTEMS GAINING ORGANIZATION. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. RIDGE PREVAILS ACROSS EASTERN SEABOARD OF U.S. WHILE CLIMO LOW PERSISTS ACROSS COLOMBIA. DEEP LAYERED TUTT EXTENDING W INTO TROPICAL N ATLC THEN SW INTO FAR E CARIB COMBINING WITH SHEARLINE ALONG 24N TO INTERRUPT PRES GRADIENT WITH ONLY FRESH ELY TRADES AND MAX SEAS 5-6 FT PREVAILING ACROSS S CENTRAL PORTIONS. SMALL NLY SWELL FROM NICOLE CONTINUES TO SPREAD INTO REGION AND THROUGH CARIB PASSAGES AND WILL INCREASE SIGNIFICANTLY MON-TUE WITH LARGE PULSE OF NNE SWELL. A BROAD AND WEAK MONSOONAL LOW IS EXPECTED TO PREVAIL ACROSS SW CARIB NEXT SEVERAL DAYS WHILE SFC LOW IS EXPECTED TO DEVELOP ALONG OR S OF THE SHEARLINE ALONG 24N AND N OF THE BASIN THROUGH MID WEEK. GFS HAS BACKED OFF OF RECENT FORECAST OF SIGNIFICANT DEVELOPMENT OF SW CARIB LOW. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. A SHEARLINE EXTENDS FROM NEAR 23N60W TO CENTRAL BAHAMAS NEAR 24N75W THROUGH THE STRAITS OF FLORIDA. LATEST ASCAT WINDS SHOW FRESHENING NE FLOW N OF SHEARLINE W OF 65W AND BROADER AREA OF 20 KT NE WINDS N AND NNE OF BAHAMAS AS E COAST RIDGE REMAINS IN PLACE. LONG PERIOD N TO NE SWELL AND MIXED WIND WAVES DOMINATING SEAS ACROSS THE ATLC WATER TODAY WITH WAVE MODELS A FEW FT LOW...WHERE SEAS AREA 8-11 FT NE OF THE SHEARLINE AND EARLIER ALTIMETER PASSES SHOWED LOCALIZED AREAS TO 12 FT N OF 30N THIS MORNING. EXPECTED WW3 LOW SWELL BIAS WITH THIS EVENT NEAR 2 FT...AND BASED ON 12Z ANALYSIS LOOK FOR ECWAVE TO BE 1-2 FT LOW AS WELL. THE SHEAR LINE WILL MEANDER AND GRADUALLY BECOME DIFFUSE THROUGH MON-TUE WHILE THE E COAST RIDGE SHIFTS SLOWLY EWD BEHIND THE EXITING NICOLE...AND TIGHTENS THE PRES GRADIENT TO THE N OF THE DYING SHEARLINE. UPPER TROUGH SWEEPING SE ACROSS NW ATLC WILL DROP INTO N PORTIONS OF AREA AND ENHANCE MOISTURE AND CONVERGENCE THAT WILL DEVELOP ALONG DYING SHEARLINE AND MODELS RESPONSE BY DEVELOPING SFC LOW ALONG THIS OLD SHEARLINE AND SHIFTING IT ENE THROUGH WED. ECMWF AND UKMET ARE E OF GFS POSITION AND HAVE TRENDED TOWARD ECMWF SOLUTION AS A MEAN POSITION FOR LOW AND TROUGH. REGARDLESS..ROUGH MARINE CONDITIONS WILL PREVAIL ACROSS W AND NW PORTIONS OF AREA THROUGH AT LEAST MID WEEK AS STRONG WINDS WILL APPROACH 30 KT BY WED N OF LOW AND/OR LINGERING TROFFING...AND COMBINE WITH MODERATE TO LARGE NE SWELL FROM NICOLE. LOOK FOR 8-9 FT OF NNE SWELL TO REACH THE NE CARIB AND LESSER ANTILLES TUE-WED. .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS II COLLABORATION 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.