000 AXNT20 KNHC 111059 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 559 AM EST Sun Nov 11 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. ...SPECIAL FEATURES... ...Gulf of Mexico Gale... A strong cold front is expected to move into the northwest Gulf of Mexico by Monday afternoon. Winds up to gale force will follow this stronger front over the western Gulf as it reaches from near Pensacola, Florida to Tampico, Mexico by late Monday. This feature will likely bring strong gales over the southwest Gulf Tue, possibly reaching storm force off Veracruz, as the front reaches from near Tampa, Florida to Coatzacoalcos, Mexico. Winds and seas will diminish Wed as the front sweeps southeast of the region. Refer to the High Seas Forecast product under AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details. ...TROPICAL WAVES... An Atlantic tropical wave is along 27W south of 09N. Scattered moderate to isolated strong convection is noted 90 nm on either side of the wave axis with scattered disorganized convection N and S of the ITCZ near the wave. An Atlantic tropical wave is along 39W/40W south of 10N. Scattered moderate convection is present 120 nm on either side of the wave axis. Scattered moderate isolated strong convection is related to the proximity of the ITCZ nearby. An Atlantic tropical wave is along 52W south of 16N. Scattered moderate convection is noted from 13N to 15N between 45W and 50W. A Caribbean tropical wave is in the Gulf of Honduras south of 19N along 85W/86W from 20N southward. No convection is observed with this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Sierra Leone near 08N13W to 07N17W. A segment of the ITCZ continues from 07N17W to west to 05N25W. Other segments of the ITCZ reach from 06N28W to 05N37W, and from 05N41W to 05N50W. Convergent trade wind flow south of strong high pressure over the central Atlantic is supporting numerous moderate to strong convection within 150 nm north and 90 nm south of the ITCZ. GULF OF MEXICO... A stationary front extends from Naples Florida to 24N96W to 18N94W. Strong easterly winds are noted in scatterometer and buoy data north of the front and north of 24N. Earlier altimeter data showed seas to 13 ft off the Mexican coast from Tampico to Veracruz, although seas are subsiding. The front will lift north and weaken as it lifts northward today ahead of a stronger cold front moving off the Texas coast by late Mon. Strong winds and building seas will follow the front, reaching gale force over the NW Gulf by late Mon. Strong gales will follow the front over the western Gulf as it reaches from Panama City Florida to Coatzacoalcos Mexico early Tue, with brief storm conditions possible off Veracruz. Winds and seas will gradually diminish Wed into Thu as the front sweeps southeast of the region. CARIBBEAN SEA... A recent scatterometer pass indicated fresh to strong NE winds pulsing through the Windward Passage. This is indicative of a relatively tighter pressure gradient between building high pressure off the U.S. east coast and troughing over the eastern Caribbean related to a sharp upper trough reaching from the central Atlantic to Puerto Rico. This pattern will persist through tonight, with areas of fresh strong winds also pulsing off the central coast of Colombia, near Cabo Beata on the southern coast of Hispaniola, and through the Gulf of Guacanayabo in southeast Cuba. Meanwhile thunderstorms and strong winds are noted on the northern portion of a tropical wave analyzed well east of the area in the tropical north Atlantic along 52W, and this is expected reach the waters northeast of the Leeward Islands by tonight. The tropical wave will drift through the eastern Caribbean by mid week. Fresh to strong trade winds and 8 to 10 ft seas with easterly swell will follow over the tropical north Atlantic region. As the tropical wave shifts east, a cold front will move into the southwest north Atlantic area to the north, temporarily weakening the subtropical ridge and allowing winds across the basin to diminish through mid week across the eastern and central Caribbean. The strong cold front will also be moving across the Gulf of Mexico, and bring fresh to strong N winds and seas to 12 ft into the Yucatan Channel and the NW Caribbean Wed through Thu. ATLANTIC OCEAN... Moderate to fresh northerly winds are observed north of a cold front extending from 31N71W to West Palm Beach Florida. Seas to 8 ft in northerly swell are also apparent, at least over waters north of 30N. Subsidence associated with a sharp upper trough is maintaining generally fair weather from Bermuda to the Turks and Caicos, but upper divergence on the eastern side of the upper trough is supporting a few showers and thunderstorms across the waters northeast of the Leeward Islands. Buoy and altimeter satellite data show generally 4 to 6 ft seas over open waters. The front will stall and weaken over the northern Bahamas through today. The front will lift north and becoming diffuse Mon ahead of a stronger front moving off the northeast Florida coast late Tue. The second front will reach from 31N73W to western Cuba Wed when a reinforcing push of cold air will bring strong northerly winds and building seas to the waters north of 27N by late Wed. As this happens, troughing on the northern end of a tropical wave will move into the waters northeast of the Leeward Islands Mon and Tue, coming into phase with favorable conditions aloft on the southeast side of the upper trough, thus enhancing convection, lowering surface pressure and allowing surface winds to increase. The resultant developing low pressure will move N-NW, reaching north of Puerto Rico Wed, before interacting with the stalling front Thu well to the northeast of the southern Bahamas. Strong to near- gale force winds are possible with this low, and it currently has a medium chance of tropical cyclone development by mid week before interacting with the stalling front to its northwest. Farther east, 1027 mb high pressure is centered near 33N43W, supporting mostly fresh trade winds over the deep tropics. Various recent altimeter passes indicate 8 to 11 ft swell across most of region. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen