000 AGXX40 KNHC 090657 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 157 AM 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... A cold front extends from Tampa Bay to the NE tip of the Yucatan Peninsula to just inland of the SW Gulf of Mexico. A thin but potent line of heavy convection is out ahead of the front with frequent lightning and winds and seas locally higher. A recent scatterometer pass showed impressive gale force winds in the Gulf S of 26N and W of 90W, including up to 45 kt just offshore in the SW Gulf. Recent altimeter passes measured large seas up to 24 ft in NW swell in the SW Gulf while NDBC Buoy 42055 has been reporting 20 ft seas for a few hours. Fresh to near gale force NW to N flow covers the remainder of the basin W of the front, with moderate to fresh winds ahead of the front. The front will shift SE of the basin through the morning with gales ending in the SW gulf shortly after sunrise. Remaining strong winds and large seas will diminish and subside from the northwest to the southeast through this coming night. Marine conditions will rapidly improve Sun 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 is just NW of the basin and the Yucatan Channel with a thin but potent line of convection out ahead of it, including just offshore of the eastern Yucatan and Belize. Generally moderate to fresh easterly tradewinds are occurring across the area, except strong breeze in the Central and NE Caribbean where seas are up to 7-9 ft. The front will pass through the Yucatan Channel in the next few hours, extending from Central Cuba to Honduras late this coming night, will reach from Eastern Cuba to Nicaragua on Sun, and stall from the Windward Passage to near Costa Rica Mon through Tue, gradually dissipating by mid-week. Strong to gale force northerly winds and building seas are expected behind the front, with frequent gusts to gale force in the NW Caribbean including the Yucatan Channel and Gulf of Honduras later today, then sustained gales possible along and offshore of the coast of Nicaragua on Sun and Mon. Meanwhile, large northerly swell will continue across the tropical Atlantic waters and the eastern Caribbean passages through this coming night. Trades will also significantly weaken through the weekend and early next week as the front disrupts the pressure gradient ahead of it. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A strong cold front is just offshore of northeastern Florida near 31N79W to near Daytona Beach. A vigorous line of convection is out ahead of the front with frequent lightning. Moderate to fresh return flow dominates the basin ahead of the front around central ATLC high pressure near 31N58W, except winds are now increasing to fresh to strong N of 27N ahead of the front. Seas are mainly 6-9 ft, except 1-3 ft inside the Bahamas. The front will shift eastward today and extend from near Bermuda to eastern Cuba on Sun, then from 28N65W to the Windward Passage on Mon, and from 27N65W to Hispaniola on Tue where it will stall and gradually dissipate through mid-week. Fresh to near gale force NW flow will follow the front, while winds ahead of it will increase to near gale force along 31N by this afternoon with minimal gales N of 31N. Winds and seas in NW swell will diminish and subside for the second half of the weekend into early next week. Another cold front will enter the 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. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... .GMZ019...CENTRAL GULF FROM 22N TO 26N BETWEEN 87W AND 94W... Gale Warning early today. .GMZ023...SW GULF S OF 22N W OF 94W... Gale Warning early today. .GMZ025...E BAY OF CAMPECHE INCLUDING CAMPECHE BANK... Gale Warning early today. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ011...CARIBBEAN N OF 18N W OF 85W INCLUDING YUCATAN BASIN... Gale Warning today into tonight. .AMZ013...CARIBBEAN N OF 18N BETWEEN 76W AND 85W INCLUDING CAYMAN BASIN... Gale Warning today into tonight. .AMZ017...GULF OF HONDURAS... Gale Warning today into tonight. .AMZ019...CARIBBEAN FROM 15N TO 18N BETWEEN 80W AND 85W... Gale Warning today into tonight. .AMZ029...W CENTRAL CARIBBEAN FROM 11N TO 15N W OF 80W... Gale Warning tonight into Sun night. .AMZ039...SW CARIBBEAN S OF 11N INCLUDING APPROACHES TO PANAMA CANAL... Gale Warning Sun into Sun night. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Lewitsky. National Hurricane Center.