000 AGXX40 KNHC 091839 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 139 PM EST Sat Dec 9 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... Strong cold front sweeping across the basin has almost cleared the far SE waters and Straits of Florida, with winds slowly beginning to diminish from NW to SE behind front. Partial ASCAT pass from 1534Z showed winds 25-30 kt across the SW gulf and Bay of Campeche, and gales there likely ended around 12Z this morning. Gales in frequent gusts are assumed to be occurring across the Yucatan Channel attm. Morning buoy and altimeter data suggested a large area of 12+ ft seas behind the front that now extend to offshore of Sarasota to near Veracruz with peak seas 20-22 ft in central Bay of Campeche and 15-16 ft just N of Yucatan Channel. The front will shift SE of the basin in the next few hours. Strong winds and large seas will diminish and subside from the northwest to the southeast through tonight, but with front lingering across SW Carib next few days, moderate to fresh Nly flow across far E portions of gulf tonight through Sun midday will maintain seas in the 7-9 ft range across SE portions and Straits of FL through Sun afternoon. Conditions will then rapidly improve through Mon. Another cold front will clip the eastern Gulf Mon night through Wed, but winds and seas will likely remain 20 kt or less and less than 8 ft. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A strong cold front has entered the NW part of the basin overnight and this morning and now extends from W Cuba to the Bay Islands of N central coast of Honduras. A trough just out ahead of S portion of the front was aiding in producing moderate NW winds ahead of the front overnight with now strong NW winds jumping across the W half of Gulf of Honduras and offshore waters of Yucatan Peninsula. 1136Z altimeter pass showed seas 6-9 ft across Gulf of Honduras along 86.5W. A recent ASCAT pass covered the NW Carib E of 85W and showed solid area of 30 kt winds behind front and off SW coast of Cuba and feel confident that gales are occurring across Yucatan Channel attm where seas are building to 12 ft. Fresh to locally strong trades prevail elsewhere across the Carib E of 76W and more NE across the tropical N Atlc waters. Seas inside the E Carib running 6-9 ft as long period NNE swell is bleeding through the passages, with seas 8 to 12 ft E of the Lesser Antilles. The front will continue ESE and is expected to extend from E Cuba to Bocas del Torro Panama area Sun morning, and begin to stall, as N part reaches Windward Passage Mon morning and begins to dissipate along NW coast of Haiti Tue morning. Gale force NWly winds behind the front are expected to develop across outer portions of Gulf of Honduras in next few hours and then shift ESE behind front and then offshore of NE coast of Honduras this evening and then spill down the coastal waters of Nicaragua tonightand likely persist through Mon morning. Seas will build quickly and have chosen higher values by EC and NWPS near 14 ft off coast of Costa Rica Sunday night. Meanwhile, large northerly swell will continue across the tropical Atlantic waters and the eastern Caribbean passages tonight. Trades will also significantly weaken through the weekend and early next week as the front and an inverted trough NE of the area disrupts the strong Atlc ridge and associated pressure gradient. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Strong cold front moving slowly E across the far NW waters and looked to be from near 31N77W to N coast of Lake O. Strong convection along the front overnight has diminished in intensity this morning but still maintaining frequent lightning. Moderate to fresh return flow dominates the basin ahead of the front around central ATLC high pressure near 33N54W, except fresh to strong N of 27N ahead of the front. Seas are mainly 7-10 ft ahead of the front, 4-8 ft behind the front, and 2-4 ft inside the Bahamas S of 26N. The front will continue to shift eastward through Tue but will begin to stall across the Carib by Sun and begin to weaken quickly on Tue. Model guidance has slowly forward motion of the front and now suggest front to reach from 31N68W to E Cuba Sun morning, from 28N65W to Windward Passage Mon morning, then begin to meander and weaken from 27N65W to NW coast of Haiti Tue morning. Fresh to strong through Sun before parent energy lifts quickly out the NNE and post frontal ridge lifts N of area to produce N to NE winds beginning Sun night. Pres gradient along stalled frontal boundary will induce 90-120 nm wide zone of strong NNE to NE winds behind front and S of 26N Mon and Mon night. Another cold front will sweep across the far NW portion Tue with another round of fresh to near gale force winds and seas building to 8-13 ft across the waters N of 27N Tue afternoon into early Wed, with conditions improving thereafter. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ011...CARIBBEAN N OF 18N W OF 85W INCLUDING YUCATAN BASIN... Gale Warning today. .AMZ013...CARIBBEAN N OF 18N BETWEEN 76W AND 85W INCLUDING CAYMAN BASIN... Gale Warning today. .AMZ017...GULF OF HONDURAS... Gale Warning today. .AMZ019...CARIBBEAN FROM 15N TO 18N BETWEEN 80W AND 85W... Gale Warning today. .AMZ029...W CENTRAL CARIBBEAN FROM 11N TO 15N W OF 80W... Gale Warning tonight into Sun. GALE CONDITIONS POSSIBLE Sun night. .AMZ039...SW CARIBBEAN S OF 11N INCLUDING APPROACHES TO PANAMA CANAL... Gale Warning Sun. GALE CONDITIONS POSSIBLE Sun night. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.