000 AGXX40 KNHC 041026 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 626 AM EDT Mon Sep 4 2017 Marine Weather Discussion for the Gulf of Mexico, Caribbean Sea, and Tropical North Atlantic from 07N to 19N between 55W and 64W and the Southwest North Atlantic including the Bahamas. ...GULF OF MEXICO... A deep-layered NE-SW trough has shifted slowly E across the eastern Gulf and left a low to mid level weakness from central FL coast to Ern Bay of Campeche. This is interacting with tropical wave energy and thermal trough shifting W off of W coast of Yucatan early this morning to produce a broad area of cyclonic turning and deep cnvtn across much of the Bay of Campeche. LLvl trough forecast to linger next several days across far W and SW Gulf looks to be present also. Models had been forecasting low pres to develop along W gulf trough in coming days, but this cyclonic turning in Bay of Campeche may refocus area of genesis. Otherwise generally tranquil conditions expected through Wed before an early season frontal boundary sinks S into the NW and N central Gulf and gradually merges with troughing across the SW through Thu. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Fresh trades expected across S central portions through Tue and light to moderate elsewhere as Irma is the main feature for the region. NE to E swell well out ahead of Irma is already moving into the Trpcl N Atlc waters and will reach NE Carib passages by afternoon. Seas to build across the Trpcl Atlc waters this afternoon and tonight while winds back and gradually increase with tropical storm force winds expected N of 14.5-15N by evening. Irma is moving WSW attm and low end of Cat 3 but could intensify as it has begun to reach warmer waters, and should turn more W by late tonight and then WNW on Tue. Models in very good agreement than Irma will track across the far N Leewards, very near and possibly across Barbuda, Anguilla, and then Anegada Tue night through Wed night. Deteriorating marine conditions will begin across these waters tonight and shift W and SW with Irma. Look for wind field to expand by Tue and extend TS force winds into far NE Carib while NE swell will also easily bleed through and into the Carib. Strong SE winds and diminishing seas to spread across the Trpcl Atlc waters Wed night through Thu as Irma exits to the WNW. All interests across the NE and E Caribbean should closely monitor the progress of Irma. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Weak frontal trough extending from offshore of NE Florida into W Atlc will shift ENE and exit area by Tue and allow N central Atlc ridge to build SW to NE Florida Tue through Thu ahead of Irma. NE to E swells from Irma are moving through waters E of Leewards this morning and will build 8-12 ft by afternoon well ahead of Irma. Major hurricane Irma is expected to flatten out trajectory late tonight and turn WNW on Tue and move across or very near the far NE islands of the Leewards. TS force winds expected across this area by Tue afternoon and will then spread WNW with Irma through Thu as the expanding hurricane tracks WNW and across or very near the far nrn VI of Anegada and Necker, and then just offshore of PR. Recent spread in the global models has diminished significantly with the 00Z runs as the GFS has shifted considerably left and very much in line with the ECMWF. In fact their locations of Irma are very close on day 3 and 4. Thus confidence in forecast trajectory is increasing. This adjusted track now moves through the Bahamas Thu through Sat, and possibly just offshore or along the N coast of Cuba. Models still show Irma blowing up in size during this time and will spread large SE swell across the entire Atlc area Wed through Fri. All interests across the NE Caribbean and Bahamas should closely monitor the progress of Irma, as well as downstream interests in Florida. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ025...OFFSHORE WATERS LEEWARD ISLANDS... Tropical Storm Warning Tue. .AMZ027...TROPICAL N ATLANTIC FROM 15N TO 19N BETWEEN 55W AND 60W... Tropical Storm Warning today. Hurricane Warning tonight into Tue. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ127...ATLANTIC FROM 19N TO 22N BETWEEN 55W AND 65W... Tropical Storm Warning tonight into Tue. $$ *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.nhc.noaa.gov/marine $$ .Forecaster Stripling. National Hurricane Center.