000 AXNT20 KNHC 200001 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 701 PM EST Wed Dec 19 2018 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...Special Features... ...GALE WARNING GULF OF MEXICO... A large area of gale force winds is expected to develop in the Gulf of Mexico Thursday afternoon along and behind a vigorous cold front. The gales will progress eastward through the Gulf, exiting the Gulf by Friday evening. Areas north of 24N between 82W-95W are forecast to experience gale force winds, with some areas as high as 40 kt. Seas across portions of the central Gulf will build to 12 ft by Thursday afternoon and as high as 20 ft by late Thursday night. ...GALE WARNING ATLANTIC OCEAN... Gale force winds are expected in the western Atlantic N of 28N between 78W-81W beginning around 20/1800 ahead of a cold front. The area of gales will expand significantly late Thursday night and early Friday morning as the cold front moves through the waters. Gale force winds are forecast through the NW Bahamas southward to 25N and between 72W-80W, including near the coast of South Florida. By late Friday, the gales will still be occurring in the area. Seas in portions of the area will build to 10-20 ft late Thursday into Friday. Please read the HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through southern coastal sections of Liberia near 05N08W to 03N14W. The ITCZ continues from 03N14W to 04N20W to 01N29W to 01N37W to 02N41W. Scattered moderate convection is noted from 01N-06N between 30W-46W. Scattered showers from 00N-05N extend west of 46W to the coast of South America. Scattered showers are seen from 03N-06N between 23W-30W. Scattered showers and isolated thunderstorms are from 03N-14N within 300 nm of the west coast of Africa. GULF OF MEXICO... A vigorous mid-upper level trough digging southward across the western Gulf of Mexico is supporting a 1006 mb surface low near the south-central coast of Louisiana near 30N92W at 19/2100 UTC. A cold front extends from the low to 28N91W to 24N93W to the coast of Mexico near 20N96W to 20N97W. A warm front extends eastward from the low to 30N89W to 29N84W. A pre-frontal squall line is ahead of the cold front from 30N89W to 26N92W. Numerous moderate and isolated strong convection is seen north of 25.5N from 88W- 92W. Scattered moderate convection is seen elsewhere within a box bounded by 30N91W 26N95W 23N95W 23N91W 31N86W 30N91W. A second area of convection is seen over the eastern Gulf. Numerous moderate and isolated strong convection with this second area of convection is seen from 24N-27N between 83W-86W. Scattered moderate convection is elsewhere from 23N-29N between 82W-86W. This includes the west coast of Florida between Sarasota and the Big Bend. Additional scattered thunderstorms are developing south of 23N extending towards the Yucatan Channel, north of the western tip of Cuba. The current cold front will continue quickly eastward across the Gulf tonight through early Fri with widespread strong thunderstorms. Strong to near gale force S winds will develop over the E waters tonight ahead of the front. Strong to near gale force westerly winds W of the front will increase to gale force on Thu with seas building to near 20 ft across the east-central waters on Thu night. A post-frontal surface high pressure will shift E across the central Gulf on Sat, and move NE across the Florida Panhandle on Sun leaving a weak ridge from the Florida Big Bend to SE Texas on Mon. CARIBBEAN SEA... Most of the Caribbean is currently experiencing fairly quiet weather with only some light to moderate trade wind showers possible over the SE Caribbean as well as the area south of the Windward Passage over toward Jamaica. Scattered showers and isolated thunderstorms are over the southern Gulf of Mexico just north of the Yucatan Channel. It is possible that some scattered thunderstorms may develop over the Yucatan Channel and far NW Caribbean overnight. Strong southerly winds will develop across the W Caribbean Sea overnight, ahead of a cold front entering the Yucatan Channel on Thursday. The front will reach from the Windward Passage to southern Nicaragua by Sat morning, then stall and gradually dissipate through Sun. Strong northerly winds are expected behind the front on Fri, increasing to near gale force along the Nicaragua coast on Fri into Sat. Elsewhere, fresh to strong winds will continue across the south central Caribbean Sea through Monday, with near gale force near the coast of Colombia each night. ATLANTIC OCEAN... A cold front passes through 32N47W to 25N60W to 23N65W, then continues as a stationary front to 22N70W to 22.5N74.5W. Scattered moderate convection is noted within 120 nm on either side of a line from 26N52W to beyond 32N46W. Showers emanating from the developing system over the southern U.S. and Gulf of Mexico have begun to spread into the Atlantic. Currently, scattered showers are noted west of 80W off the coast of Georgia through central Florida. Expect thunderstorm coverage to increase over the western Atlantic on Thursday as a squall line and cold front approaches from the west. The remnants of the front currently from 23N65W to 22.5N74.5W will lift N across the central waters through Thu. Strong southerly flow will develop N of the Bahamas early Thu, with strong to near gale force winds spreading S to 22N while increasing to minimal gale force N of 24N late Thu on both sides of a strong cold front moving off the SE United States coast. The front will reach from 30N75W to central Cuba on Fri, and from Bermuda to the Windward Passage on Sat. Strong to near gale force winds are expected across the Straits of Florida, the northern and the central Bahamas Thu and Fri. Strong to severe thunderstorms are also expected prior to and along with the frontal passage Thursday afternoon into early Friday. Locally enhanced winds and seas can be expected near the stronger thunderstorms. Winds will diminish from the W on Sat with seas less than 8 ft on Sun night. For additional information please visit http://www.hurricanes.gov/marine $$ Hagen