000 AGXX40 KNHC 180616 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 116 AM EST Mon Dec 18 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 frontal trough that extends from the extreme W Florida Panhandle to near Vera Cruz, Mexico will move NW this morning and onshore from Louisiana to Texas to NE Mexico by this afternoon. Scattered thunderstorms will remain possible mainly N of 28N within 90 nmi of either side of the trough. Mainly moderate to fresh SE winds and seas of 3 to 5 ft will prevail east of the surface trough as high pressure becomes established just east of the Florida peninsula tonight through Tuesday. Light winds can be expected W of the trough before it moves onshore. A weak cold front is forecast to reach the NW Gulf Wednesday and then reposition across the northern portion of the basin from west to east as a stationary front on Thursday. No significant increase in winds and seas are expected with this front. However, this front will be the focus for shower and isolated thunderstorms. The front will then lift north as a warm front Friday morning. During this Wednesday through Thursday night timeframe a ridge axis will extend from Atlantic high pressure across the southern Gulf supporting light winds and seas of 1 to 3 ft. In the mid to long range, forecast models are in good agreement on a strong cold front reaching the NW gulf by Friday afternoon accompanied by showers and thunderstorms and followed by strong NE winds through Saturday as the front moves to the central Gulf. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... High pressure to the N of the basin will remain sufficiently strong to support a tight pressure gradient over the central Caribbean through Tuesday night, capable of producing nocturnal Gale force winds north of the NW coast of Colombia. Fresh to strong E to NE winds are expected elsewhere over the central Caribbean, including the Windward Passage through this time frame. The high pressure will weaken through Wednesday and will shift SE which will diminish winds by about 3 to 5 kt over the central Caribbean, likely keeping winds just below gale force N of NW Colombia Wednesday and Thursday nights. The stronger winds early this week will be supporting seas to 14 ft during the mornings through Tuesday morning, with a large area of 8 to 12 ft extending across the central and SW Caribbean during that time. Elsewhere over the Caribbean, mainly moderate to locally fresh E to NE can be expected the next several days with generally dry conditions. Late this week forecast models are indicating that the high pressure will re-intensify, which may bring about nocturnal gales north of the NW coast of Colombia once again beginning Friday night. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A weakening cold front extending from 23N65W to the SE Bahamas will dissipate today. High pressure is building in the wake of the front and will become centered just east of central Florida today through Tuesday night. This pattern will support gentle winds and seas of 3 to 5 ft N of 26N, with moderate to fresh NE winds S of 26N, and seas of 5 to 7 ft outside of the Bahamas. The high will weaken and shift SE Wednesday, becoming centered east of the Bahamas near 25N70W through Thursday. This will allow for fairly benign marine conditions across the waters S of 31N and N of 23N during this time frame. The only exception will be the potential of a cold front to clip the waters N of 29N, with a brief period of fresh to strong SW winds expected to develop out ahead of the front late Wednesday through Thursday as it quickly moves east across our waters from north Florida to 65W. Meanwhile, S of 23N, the periphery of the high will support moderate to fresh NE to E winds Wednesday through Thursday. On Friday, high pressure will build from the north in the wake of the cold front, supporting mainly moderate E to SE winds N of 25N and moderate to fresh E winds S of 25N. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ031...CARIBBEAN FROM 11N TO 15N BETWEEN 72W AND 80W INCLUDING COLOMBIA BASIN... Gale Warning early today into tonight. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Latto. National Hurricane Center.