000 AXNT20 KNHC 042332 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 732 PM EDT Fri May 4 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 2315 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic ocean near the Sierra Leone/Liberia border and continues to the Equator at 26W. The Intertropical Convergence Zone stretches from 00N26W to 02S32W to 01S39W to NE Brazil near 02S45W. A cluster of moderate to isolated strong convection is from 03N to 07N between 11W and 16W. Scattered moderate to isolated strong convection is noted within about 120 nm S of the ITCZ axis W of 30W. ...DISCUSSION... GULF OF MEXICO... A surface ridge extends east to west from the western Atlantic along the northern Gulf coast to eastern Louisiana, with a 1022 mb high pressure center over southern Georgia. Gentle to moderate anticylonic flow is noted across the Gulf waters under the influence of the ridge. A cold front is approaching the coast of Texas. It is forecast to enter the NW Gulf late tonight, and dissipate from southern Louisiana to southern Texas by Sat night. Farther south, a thermal trough will develop over the northwest coast of Yucatan during the evening, and drift westward across the SW Gulf before dissipating later in the morning. A surge of fresh to occasionally strong NE to E winds will accompany this trough. This pattern will repeat each evening through the period. For the forecast, moderate to fresh winds over the southeast Gulf and the Straits of Florida will back more to the NE through early Sat ahead of the trough moving from the western Atlc across Florida. Scattered showers and thunderstorms will accompany the trough as it moves into the eastern Gulf early Sun before stalling and weakening. The ridge will weaken as well and high pressure will shift west through the lower Mississippi Valley, allowing moderate northerly flow and 2 to 4 ft seas through mid week. CARIBBEAN SEA... Scattered to numerous showers and tstms have flared up this afternoon across eastern Cuba, and parts of Hispaniola and Jamaica, including also the Windward Passage. This convective activity is associated with a surface trough extending across the SE Bahamas and eastern Cuba to near 18N75W, and a prominent mid/upper low currently centered over eastern Cuba. Abundant tropical moisture combined with atmospheric instability associated with the mid/upper level low will provide more thunderstorm potential to parts of Cuba, the Bahamas, Hispaniola and Jamaica on Sat. Winds have increased across the eastern Caribbean in the wake of the trough axis. Latest scatterometer data indicate fresh E-SE winds across the eastern Caribbean, and moderate to locally fresh NE winds in the lee of eastern Cuba ahead of the trough. Only moderate winds are noted near the coast of Colombia. Fresh easterly winds will prevail in the eastern Caribbean and tropical N Atlantic waters on Sat. The trough will move westward reaching Florida on Sat. ATLANTIC OCEAN... The main weather maker remains a mid/upper level low centered now over central Cuba, driving a surface trough that extends from 28N72W across eastern Cuba to near 18N75W. The most recent scatterometer data indicate fresh to strong E-SE winds of 20-25 kt E of the trough axis to about 60W, with seas to 9 ft. Fresh to strong NE winds of 20-30 kt are ahead of the trough. The strongest winds are between the trough axis and just E of the Bahamas. Tropical moisture transported by the SE winds in the wake of the trough combined with the mid/upper level low continue to support scattered to numerous showers across the Bahamas and the Turks and Caicos Islands. The trough will sharpen and elongate as it moves westward, reaching Florida this Sat, increasing the likelihood of showers and tstms over South Florida and the Florida Keys. Doppler radar shows now the first round of showers approaching SE Florida from the NW Bahamas. Strong to near gale force winds will accompany the trough, as well as numerous showers and scattered thunderstorms across the Bahamas through Sat. Scattered thunderstorms are possible across the Bahamas and adjacent waters into Sun as the upper low slowly drifts south-southwestward. Winds and seas will start to diminish Sun through early next week as through lifts northward to off the northeast coast of Florida through Mon, and the ridge weakens, but hold in place along roughly 28N/29N. The remainder of the Atlantic is under the influence of a 1028 mb high pressure located E of Bermuda near 32N56W. This system is producing moderate to fresh trade winds across the deep tropics, where seas are reaching 6 to 8 ft in NE to E swell. For additional information please visit http://www.hurricanes.gov/marine $$ GR/MT