000 AGXX40 KNHC 031038 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 638 AM EDT Sun Sep 3 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 trough has stalled NE to SW across the Gulf and continues to enhance cnvtn to its SE and E. Abundant tropical moisture will continue to spread NE across Ern portions and Florida and spread W across the S Gulf through tonight for continued active weather. High pressure will meander across the N central and NE Gulf through early next week. A trough develops in the SW Gulf and will move to along the Mexican coast Tue and Wed. Some guidance develops a broad low along the trough but of little consequence attm. The first front of the season will drop into the N Gulf Wed or Wed night and gradually merge with the through in the SW Gulf to produce strong N to NNE flow NW and W portions Thu. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Weak high pres across the W Atlc just E of Bermuda last night has collapsed, with main ridge now centered across the E central Atlc. The diminished pres gradient is only producing fresh winds S of 14N off the coast of Colombia and NW Venezuela, where seas are 5-7 ft. Otherwise seasonally mild conditions across the basin. Little overall change expected through Tue before Hurricane Irma approaches the Tropical N Atlc waters. Irma has begun the WSW dip overnight and is fluctuating near Cat 3 intensity. The forecast trajectory has shifted slightly S again as the 00Z ECMWF again came in on the Srn edge of the models but is not alone. Ely swell ahead of Irma will move into the Trpcl N Atlc waters within 24 hrs while TS winds will begin to spread into the far NE waters by late Mon-early Tue with conditions deteriorating quickly thereafter. TS winds will shift WNW with Irma through Wed and into the Atlc waters N of the VI and PR. Associated ENE swell will bleed through the NE Carib passages during this time. All interests across the NE Carib should closely monitor the changing forecasts for Irma. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A weak and narrow ridge extends SW into the area from high pres centered across the NW Atlc, while a lingering frontal boundary is strung out across the NE of the area waters. Nly swell generated from low that developed from PTC 10 across the N Atlc continues to affect most of area N through NE of Bahamas, with overnight buoys and altimeter obs showing the swell 2 ft above guidance. Best energy now E of 65W or so and has peaked past 12 hours and will fade through this evening. Moderate to fresh E trades will prevail S of 22N and into S Bahamas, while gentle to moderate winds will prevail elsewhere through early Tue. As mentioned above, Hurricane Irma is expected to approach the Leewards Tue and move WNW and pass just N of the islands late Tue through late Wed. Recent models runs are beginning to cluster offshore of the NE Carib islands, but the ECMWF and UKMET still are taking a more Srn track which cold yield TS winds and possibly HRCN force winds across the outer waters of PR and VI as well as N Leewards. Trajectories are then very near the SE Bahamas and or parallel to island chain but confidence still not moderate attm beyond day 3-4. All interests across the NE Carib and Bahamas should continue to monitor Irma closely, as all global models show a major hurricane with expanding wind field after moving W of 70W. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ027...TROPICAL N ATLANTIC FROM 15N TO 19N BETWEEN 55W AND 60W... Tropical Storm Warning Mon. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.nhc.noaa.gov/marine $$ .Forecaster Stripling. National Hurricane Center.