000 AXNT20 KNHC 171803 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 203 PM EDT Sat Mar 17 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 1745 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 09.5N13W to 05N19W. The ITCZ continues from that position to 02N30W and then extends to the coast of Brazil near 01N50W. Scattered showers and tstms are within 210 nm off the coast of Liberia, Africa and within 195 nm either side of the monsoon trough and ITCZ E of 35W. ...DISCUSSION... GULF OF MEXICO... A surface ridge anchored by a 1021 mb high E of the northern Bahamas continue to provide gentle to moderate southeast winds, with seas 3 to 4 ft over the western half of the basin and 1 to 3 ft in the eastern Gulf. Areas of sea fog and haze continue to be reported in the northwest Gulf. The ridge will shift east Sun night ahead of a cold front moving off the Texas coast offshore Texas Mon evening. The front will extend from the Florida Big Bend area to Tampico, Mexico Tue afternoon being reinforced by a push of cold air that will move off the Texas coast earlier that day. Fresh to strong winds and building seas over the northern Gulf will be associated with this second push of cold air that will merge with the leading front Tue evening. The merged front will sweep southeast of the Gulf by early Wed. Winds and seas diminish across the Gulf through late Wed as high pressure follows the front across the northern Gulf. CARIBBEAN SEA... The undersea volcano Kick 'em Jenny, located 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 / 3.1 nm exclusion zone around Kick 'em Jenny. Please see http://nadma.gd for further information. A ridge centered by a 1021 mb high east of the northern Bahamas is supporting fresh to strong trade winds over the south-central Caribbean, off the coast of northwestern Venezuela and northeastern Colombia. The latest scatterometer pass, however, show up to 30 kt winds along the coast of Colombia. Seas in this area remain 8 to 10 ft per the latest observations. Moderate to fresh trades are observed S of 17N over the eastern basin and remaining central Caribbean waters. Gentle to moderate winds are noted elsewhere with mostly 3 to 5 ft seas. Moderate trades are east of the Leeward and Windward Islands with buoy data indicating 8 to 10 ft seas in northerly swell. Otherwise, moderate trades are in the Gulf of Honduras according to latest scatterometer data. The tail of a cold front is forecast to pass through the Yucatan Channel Wednesday morning. High pressure building behind the front in the Gulf of Mexico will allow fresh north-northeasterly winds in the NW basin Wed night through Thursday morning. ATLANTIC OCEAN... A cold front extends from 30N57W to 28N63W to 30N70W accompanied by few showers, fresh to strong W to NW winds and seas of 8 to 12 ft. A ridge anchored by a 1021 mb high just east of the northern Bahamas dominates the waters W of 65W S of the front and maintains generally light to gentle winds. Seas are 6 to 9 ft in open waters primarily due to northerly swell. The cold front will weaken as it shifts east to the central Atlc Sunday morning. W winds will increase north of 28N late Sun as low pressure moves off the Carolinas along with another cold front, shifting east of the area through Mon morning. Southerly winds will increase off northeast Florida and north of the Bahamas Mon evening, then increasing further to near gale force north of 27N with 8 to 12 ft seas by Tue night as a stronger low pressure system moves off the Carolina coast. The remnants of a former stationary front are analyzed as a surface trough that extends from 30N48W to 25N58W to north-central Hispaniola coast. Scattered showers are within 90 nm either side of the boundary N of 24N. Isolated showers are in the remainder southern portion of the trough. Over the eastern Atlantic, 1025 mb high pressure is centered near 28N27W, and this is maintaining gentle flow over the subtropics and moderate to fresh flow in the deep tropics. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos