000 AXNT20 KNHC 171053 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 653 AM 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 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 09.5N14W to 06N20W. The ITCZ continues from that position to 00N33W and then extends to the coast of Brazil near 00N49W. Scattered showers is noted between 60 nm on either side of the ITCZ between 15N and 40N. ...DISCUSSION... GULF OF MEXICO... A ridge extends from 1020 mb high pressure over the northeast Gulf of Mexico to the coast of Texas. The ridge is supporting gentle to moderate southeast winds, with seas 2 to 4 ft over the western Gulf and 1 to 3 ft in the eastern Gulf. Dewpoints are in the lower 70s over the northwest Gulf in the area of moist southeast flow. Areas of sea fog in the northwest Gulf are noticeable in satellite imagery and among some of the observations from regional platform observations with visibilities ranging from 3 to 5 nm. The ridge will shift east Sun night ahead of a cold front moving off the Texas coast offshore Texas Mon. The front will extend from the Florida Big Bend area to Veracruz Mexico early Tue, 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 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. High pressure centered near the Bahamas is supporting fresh to strong trade winds over the south central Caribbean, off the coast of northwestern Venezuela and northeastern Colombia. Seas in this area are 8 to 10 ft as observed in recent altimeter satellite passes. Light to gentle breezes are noted elsewhere with mostly 3 to 5 ft seas. Moderate trades are noted east of the Leeward and Windward Islands, but buoy and altimeter satellite passes indicate 8 to 10 ft seas, likely in northerly swell. Regional radar shows isolated showers across the Windward Islands. A weakening cold front will pass through the Yucatan Basin late Tue night. High pressure building behind the front will allow fresh to strong easterly winds near the Gulf of Honduras Mon night into Tue. ATLANTIC OCEAN... A cold front is reaching 30N, between 67W and 70W, accompanied by few showers and thunderstorms, fresh to strong W to NW winds and seas of 8 to 12 ft as noted in recent buoy and altimeter reports. Farther south, a stationary front is weakening to a trough from from 23N65W to the Windward Passage. 1021 mb high pressure is centered off the northern Bahamas near 26N75W is maintaining generally light to gentle winds across the region outside the area of fresh to strong winds near the cold front. Seas are 5 to 7 ft in open waters primarily due to northerly swell. The cold front will shift east of the area through this morning, along with the strong winds. Seas of 8 to 12 ft will linger through into Sun north of 28N east of 70W. W winds will increase north of 28N late Sun as low pressure moves off the Carolinas along another cold front, shifting east of the area through late Mon. Southerly winds will increase off northeast Florida and north of the Bahamas late Mon, then increasing further to near gale force north of 27N with 8 to 12 ft seas by Tue night as the low pressure moves off the Carolina coast. Over the eastern Atlantic, 1024 mb high pressure is centered near 29N37W, and this is maintaining gentle flow over the subtropics and moderate to fresh flow in the deep tropics. Trade wind convergence is supporting scattered showers and a few thunderstorms along and north of the ITCZ. Recent altimeter satellite passes are showing seas 8 to 11 ft in primarily NW swell. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen