000 AGXX40 KNHC 050608 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 208 AM EDT Thu Oct 5 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 tight pressure gradient remains in place between strong high pressure over the U.S. Mid-Atlantic region and elongated surface troughing just E of the Florida Peninsula. Fresh to strong NE to E flow prevails across the basin, except moderate to locally fresh in the SW Gulf. Seas are 7 to 11 ft across the majority of the basin, except 4 to 7 ft in the SW Gulf. The surface troughing E of Florida will move across the peninsula through the morning, then through the E Gulf through this afternoon, reaching the central Gulf by early Fri, then shifting NW of the area through early Sat. Weak surface low pres may develop along the trough today, but tropical cyclone formation is not anticipated. Tropical Depression Sixteen currently in the western Caribbean Sea is forecast to reach the NW Caribbean early Fri, then will move over the NE tip of the Yucatan Peninsula or through the Yucatan Channel Fri night, and into the S central or SE Gulf into early Sat as a Tropical Storm. The system is then forecast to reach hurricane strength by 72 hours in the central Gulf. The official forecast then has the system approaching the Gulf coast between the Florida Peninsula and SE Louisiana by early Sun, moving inland through Sun night. Please visit hurricanes.gov for the latest forecast and more details on this system. High pres ridging will build in the wake of the system for the early part of next week with more tranquil marine conditions anticipated. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Tropical Depression Sixteen was located near 13.0N 83.0W in the SW Caribbean Sea offshore of the Caribbean coast of Nicaragua at 0600 UTC. The system is forecast to strengthen to a tropical storm later this morning, then will move inland across eastern Nicaragua and Honduras through this evening, then is forecast to emerge in the NW Caribbean Sea near the eastern portion of the Gulf of Honduras during the overnight hours, then move over the NE tip of the Yucatan Peninsula or through the Yucatan Channel Fri night. Maximum seas will build to up to 20 ft as the system moves through the NW Caribbean. The system then will quickly pull away from the Caribbean with winds and seas diminishing and subsiding across the approach to the Yucatan Channel through Sat evening. Please visit hurricanes.gov for the latest forecast and more details on this system. Otherwise, a tropical wave is in the eastern Caribbean extending from near the Mona Passage to northern Venezuela. Convective activity is limited with this wave. Mainly moderate E to SE winds and 3 to 5 ft seas dominate the basin outside of the influence of the tropical depression. Expect light to moderate trades to prevail in the wake of the tropical system for the second half of the upcoming weekend into early next week. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A vigorous surface trough extends from near 27N76W to across the western Bahamas to central Cuba with numerous showers and scattered thunderstorms W of 70W. Recent scatterometer and buoy data indicate gusts to gale force S of 27N and W of the Bahamas where a gale warning for frequent gusts remains in effect for these offshore waters, as well as the Miami Weather Forecast Office coastal waters. Fresh to strong NE to E flow dominates the remainder of the basin N of 23N. Large seas of 8 to 14 ft prevail across these same waters with a persistent and expansive NE to E fetch. The northern extent of a tropical wave extends from near the Mona Passage to near 25N67W. Most of the associated convection is E of the offshore waters, except in zone AMZ127W where scattered showers and isolated thunderstorms are occurring. The surface trough will shift W across the Florida Peninsula through the morning hours and the pressure gradient is forecast to significantly weaken in its wake. Winds will become E to SE at moderate to locally fresh levels across the basin this evening into the overnight hours, while the tropical wave continues westward with little impact other than a wind shift. Winds will continue to diminish during Fri to gentle to moderate, with seas also continuing to subside to 4 to 7 ft at that same time. A trough is forecast to develop over the eastern waters on Sat where it will linger into early Sun with possible weak low pres developing along it. The pressure gradient will increase on the NE side of the trough increasing winds to fresh, however the gradient will remain weak elsewhere across the basin. Moderate E to SE flow and 4 to 7 ft seas will then prevail later Sun into early next week as the troughing dissipates. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... .GMZ019...CENTRAL GULF FROM 22N TO 26N BETWEEN 87W AND 94W... Tropical Storm Warning Fri night. .GMZ021...E GULF FROM 22N TO 25N E OF 87W INCLUDING STRAITS OF FLORIDA... Tropical Storm Warning Fri night. .GMZ025...E BAY OF CAMPECHE INCLUDING CAMPECHE BANK... Tropical Storm Warning Fri night. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ011...CARIBBEAN N OF 18N W OF 85W INCLUDING YUCATAN BASIN... Tropical Storm Warning Fri into Fri night. .AMZ013...CARIBBEAN N OF 18N BETWEEN 76W AND 85W INCLUDING CAYMAN BASIN... Tropical Storm Warning Fri. .AMZ017...GULF OF HONDURAS... Tropical Storm Warning tonight into Fri. .AMZ019...CARIBBEAN FROM 15N TO 18N BETWEEN 80W AND 85W... Tropical Storm Warning tonight into Fri. .AMZ029...W CENTRAL CARIBBEAN FROM 11N TO 15N W OF 80W... Tropical Storm Warning today. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ117...BAHAMAS INCLUDING CAY SAL BANK... Gale Warning early today. $$ *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 Lewitsky. National Hurricane Center.