000 AXNT20 KNHC 180605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT TUE OCT 18 2016 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 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...SPECIAL FEATURES... Tropical Storm Nicole is centered near 44.8N 41.0W at 0300 UTC or about 520 nm E of Cape Race Newfoundland, accelerating toward the NE at 22 kt. Estimated minimum central pressure is 968 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Widely scattered moderate convection is N of 40N between 35W and 45W. Nicole should transition to an extratropical cyclone on Tuesday. Large swells associated with Nicole will affect the United States east coast, the coast of Atlantic Canada, Bermuda, the Bahamas, the Greater Antilles, the Leeward Islands, and the Azores islands for the next few days, creating dangerous surf conditions and rip currents. These swells are also likely to reach Europe and the northwest coast of Africa in a day or two. See latest Forecast/Advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC for more details. ...TROPICAL WAVES... Tropical wave is in the eastern Atlantic extending from 07N to 15N with axis near 27W, expected to move W at 5-10 kt over the next 24 hours. The wave is in a region of unfavorable deep layer wind shear and CIRA LPW imagery from surface to 850 mb show pockets of dry air in the wave environment. Shallow moisture and divergent wind flow aloft support scattered showers from 07N to 16N E of 30W, including the Cape Verde Islands. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 12N16W to 06N22W to 04N37W. The ITCZ begins near 05N42W and continues along 08N53W to 08N60W. Aside from the convection associated with the tropical wave, widely scattered moderate convection is from 0N to 06N between 10W and 40W. ...DISCUSSION... GULF OF MEXICO... A broad surface ridge anchored by a 1018 mb high over Atlantic waters near 34N70W extends SW across the SE CONUS and into the Gulf where it provides gentle to moderate E to SE flow, except over the E Bay of Campeche where winds are from the NE. Middle to upper level ridging and strong dry air subsidence support stable and fair weather conditions. Gentle to moderate anticyclonic winds are expected to persist today, increasing slightly tonight into Wednesday. The next cold front is expected to emerge off the Texas and Louisiana coasts by Thursday night into early Friday. CARIBBEAN SEA... A broad and elongated middle level trough extends across the W Atlantic W of 60W and into the W Caribbean to a base over Panama coastal waters. This middle level feature along with abundant moisture in the region and favorable deep layer wind shear support scattered showers within 90 nm of the Central America coast as well as S of 20N between 67W and 82W. The extension of this trough to the upper levels with a base across the central Bahamas and upper ridging across the E Caribbean generate diffluent flow just N of Hispaniola and Puerto Rico, thus supporting scattered to isolated showers in both islands and adjacent waters. Generally low pressure is across the basin at the surface with gentle to moderate S to SE winds in the E half of the Caribbean and light NE flow elsewhere W of 80W. Global models are suggesting cyclogenesis to occur N of Hispaniola and Puerto Rico today, which is already resulting in a disruption of the usual trade wind flow across the eastern Caribbean. As a low center organizes today through Wednesday and lifts generally northward, lingering weak surface troughing will extend across the Greater Antilles into the SW Caribbean through Saturday. ...HISPANIOLA... An upper trough over the W Atlantic waters with a base reaching the central Bahamas and an upper ridge between 50W and 65W generate diffluent flow to the NNE of Hispaniola, thus supporting scattered showers across Haiti and the Windward Passage and isolated showers in the Dominican Republic. The island is expected to remain within an area of weak surface troughing through Wednesday as cyclogenesis occurs across the SW North Atlc waters overnight through Wednesday. Showers are expected to increase Tuesday night and continue through the middle of the week. ATLANTIC OCEAN... A middle to upper level trough is noted on water vapor imagery over the W Atlc, with a relatively broad base reaching the central Bahamas. The troughing aloft is supporting a 1006 mb low near 23N72W and a large area of heavy showers and tstms from 19N to 25N between 64W and 70W. The low pressure is forecast to shift ENE this morning, then attempt to become better organized later today as it begins to lift northward. Strong easterly winds are expected to occur within 240 nm across northern portions of this low and a shearline that extends from 20N52W to 22N63W to the low center. Farther east, the central Atlc is under the influence of a stationary front extending from the circulation associated with Tropical Storm Nicole well to the N of the discussion area. The front extends from 30N39W SW to 20N51W it transitions to a shear line. Surface ridging is elsewhere in the eastern Atlantic. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS