000 AXNT20 KNHC 311058 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 558 AM EST Mon Dec 31 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... ...GALE WARNING IN THE CARIBBEAN SEA... Strong high pressure north of the region will support fresh to strong winds across mainly the central Caribbean through the week. Gale force winds will pulse off the coast of Colombia mainly during overnight and early morning hours through mid week. Please refer to the High Seas forecast product under the AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Liberia near 04N07W to 04N18W. The ITCZ continues from 04N18W to 00N40W. Scattered moderate to isolated strong rainshowers are observed within 90 nm either side of the monsoon trough between 10W and 18W. Scattered moderate convection from 03N to 07N between 25W and 38W. GULF OF MEXICO... Platforms across the northwest Gulf are reporting areas of fog, with visibilities varying widely from 1 nm up to 6 nm. Satellite imagery indicates fog is likely also in place over the northeast Gulf, where relatively warmer moist air is flowing northward across cooler shelf waters. Dense fog advisories are in effect into the morning for coastal waters from the Florida Big Bend region to southeast Louisiana, as well as over Texas nearshore waters. The fog covers much of the northern Gulf east of a frontal boundary currently stalled from the Sabine Pass to south of Tampico Mexico. The front will drift east through early Tue, then stall again late Tue from Mobile Bay to Tampico, before reversing course and moving north of the area as a warm front through mid week. The front will again change direction and move back into the NW Gulf Thu as an upper disturbance moves into the southern Plains. Strong winds will follow the front as it sweeps SE of the Gulf through early Fri, with minimal gales possible off Veracruz Mexico by late Fri. Winds and seas will diminish starting Fri night as high pressure builds across the Gulf in the wake of the front. CARIBBEAN SEA... A scatterometer pass from around 02 UTC confirmed gale force winds off the central coast of Colombia. Seas are at least 10 to 13 ft in the area of gales, and 7 to 10 ft elsewhere over the eastern and central Caribbean. No significant convection is noted at this time anywhere across the basin. High pressure north of the area will support strong to near gale force trade winds across the central Caribbean through Fri, pulsing to gale force along the NW coast of Colombia each night through the middle of each morning before diminishing. Locally strong nocturnal trades are forecast across the western Gulf of Honduras and into the Windward Passage through Tue night. Moderate to fresh trades expected elsewhere into Fri. A cold front will move through the Yucatan Channel early Fri, before stalling from central Cuba to northern Belize Fri night. ATLANTIC OCEAN... West of 55W, ridging along 28N anchored by 1025 mb high pressure near 27N67W. The ridge is maintaining generally light to gentle to winds north of 24N, with seas 5 to 7 ft in open waters outside of the Bahamas. Fresh to occasionally strong trade winds are pulsing north of Haiti and through the Turks and Caicos and the approaches to the Windward Passage. For the forecast, the ridge will dissipate through the morning as a cold front moves through the central Atlc east of the region. High pressure will build NE of the area in the wake of the front, and the ridge will again become re- established along 28N Tue and Wed. This pattern will continue to support pulses of fresh to strong trade winds north of Haiti near the approaches to the Windward Passage through mid week. A second front will move off the NE Florida coast late Thu, and reach from Bermuda to central Cuba by late Fri. Farther east, a scattered showers and isolated thunderstorms are active north of 30N between 45W and 55W, along an approaching cold front, moving southward out of the central Atlantic. Recent altimeter satellite passes along with buoy observations confirmed a large area of 8 to 12 ft seas as far south as 08N. This is primarily due to long period NW swell, but also includes a secondary component of shorter period trade wind swell south of 20N. Seas of 8 to 10 ft are reaching the Atlantic passages of the Leeward and Windward Islands. The swell will gradually subside over the next couple of days, just ahead of the cold front moving into the waters north of 24N between 35W and 55W. Strong winds will likely accompany the front in this region, maintaining seas of 8 to 12 ft along with persistent NW swell. Over the eastern north Atlantic, modest trade wind convergence in the lower levels of the atmosphere along with favorable dynamics aloft are together supporting scattered moderate to isolated strong thunderstorm activity along the monsoon trough. Farther north, a cold front is passing eastward over the waters north of 20N anchored by a 1011 mb low pressure area near the Azores Islands. NW swell of mainly 8 to 12 ft is evident over most of the waters north of 15N. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen