000 AXNT20 KNHC 191741 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 141 PM EDT Mon Mar 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Atlantic Gale Warning: Southerly flow will increase off northeast Florida late tonight and Tue ahead of a cold front moving into the region late Tue. SW to W winds will reach gale force north of 29N E of front to 76W late Tue through Wed as the front moves east. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 07N12W to 04N20W. The intertropical convergence zone continues from that point to 02N30W to 03N51W. A few showers are noted within 150 nm on either side of the ITCZ between 20W and 32W. ...DISCUSSION... GULF OF MEXICO... As of 1500 UTC, a prefrontal trough has entered the NW Gulf of Mexico. A cold front is just inland over Texas. Scattered showers are along the front. Weak ridging extends from southeast Florida to the north central Gulf, supporting light to gentle southeast winds over most of the region. Radar imagery shows scattered moderate convection over the NE Gulf and Florida N of 28N between 81W and 87W. The front will extend from the Florida Big Bend area to Veracruz Mexico tonight, just as a reinforcing push of cold air moves off the Texas coast. The reinforcing front overtakes the first front late Tue, accompanied by strong winds and building seas over the northern Gulf. The merged front sweeps southeast of the Gulf by early Wed. Winds and seas diminish across the Gulf through Thu as high pressure follows the front across the northern Gulf. CARIBBEAN SEA... A pair of scatterometer passes confirmed a large area of fresh to strong trade winds off Colombia, and a smaller area of strong winds south of the Bay Islands off central Honduras. Seas are reaching 8 ft off Colombia, but are generally 4 to 6 ft in the eastern and central Caribbean and tropical north Atlantic, and 2 to 4 ft in the northwest Caribbean. No significant convection is noted. Building high pressure north of the region will support fresh to locally strong trades across the south central Caribbean the next several days, except increasing to near gale force along the northwest coast of Colombia during the overnight hours. A cold front will pass through the Yucatan Basin by early Wed, then drift south and stall from the Windward Passage to central Honduras Fri, followed by fresh northerly flow and seas building to 7 ft. Undersea volcano Kick'em Jenny, north of Grenada near 12.18N 61.38W, is in a state of unrest. The government of Grenada advises mariners to observe a 5 km or 3.1 nm exclusion zone around Kick'em Jenny. Please see www.nadma.gd for additional information. ATLANTIC OCEAN... Please see Special Features section for information on the developing gale warning in the Atlantic. A cold front is over the W Atlantic from 31N57W to 27N70W. Scattered moderate convection is within 60 nm of the front. The front will shift eastward and weaken through Tue. Farther south, weak ridging is supporting gentle breezes west of 60W, with 4 to 6 ft seas in open waters east of 75W, due mainly to residual northerly swell. The next cold front will move off the coast late Tue, associated with a deep surface low moving off the mid-Atlantic coast. The supporting upper trough will become negatively tilted as it emerges off the coast. This will interact with the Gulf Stream to support scattered thunderstorms Tue night off the northeast coast of Florida. In addition to the gales, strong westerly winds and seas ranging from 8 ft to as high as 17 ft will prevail north of 27N and west of 60W into Wed night. Winds and seas will diminish Thu as the front reaches from Bermuda to the Windward Passage, before stalling and weakening through late week. A weaker front will move eastward north of 28N Thu night into Fri. Over the eastern Atlantic, 1028 mb high pressure is centered near 31N27W, supporting gentle to moderate NE to E winds over the subtropics and moderate to fresh trades in the deep tropics. An upper trough is noted along 28W north of 05N, supporting a few small areas of modest convection along the monsoon trough and ITCZ. Recent altimeter satellite passes indicate seas are still 8 to 12 ft north of 05N, likely in persistent long period NW swell. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa