000 AXNT20 KNHC 191106 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 706 AM EDT Fri Apr 19 2019 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 1050 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning... As of 0900 UTC, the main Gulf of Mexico cold front extends from just east of Pensacola Florida to 25N89W to 18N93W. A pre-frontal squall line is located about 30 to 45 nm ahead of the front north of 24.5N. Latest satellite and radar imagery show scattered to numerous moderate convection within 60 nm either side of the squall line. Gale force winds are possible today east of the cold front near the squall line in the NE Gulf north of 26N. A secondary cold front at 0900 UTC extends from near Slidell Louisiana to Grand Isle Louisiana to 25N92W. Near gales are currently occurring west of this secondary front with gusts to gale force. The two cold fronts are forecast to merge later this morning. Additional gale force winds are forecast in the NE Gulf this afternoon behind the merged cold front. The gales in the Gulf are forecast to end by this evening. Please refer to the Atlantic High Seas Forecast at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. Atlantic Gale Warning... The cold front is expected to move off the Florida Peninsula tonight. Gale force southerly winds are forecast ahead of the front N of 28N between 70W and the east coast of northern Florida along with numerous thunderstorms and seas of 10 to 15 feet. The gales will begin in the waters east of northern Florida early this morning around 1200 UTC. The area of gales will be east of 76W by Saturday morning. Please refer to the Atlantic High Seas Forecast at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coasts of Sierra Leone and Guinea near 09N13W to 03N18W. The ITCZ continues from 03N18W to 03S27W to the coast of Brazil near 06S35W. Scattered moderate convection is seen from 04S-03N between 14W and the coast of South America. Scattered to numerous moderate to strong convection is seen from 02N-08N between 03W-14W. GULF OF MEXICO... The cold fronts, squall line, convection and gales over the Gulf of Mexico are described extensively in the section above. Farther south, scattered showers are seen in the southern Bay of Campeche south of 20S. Scattered thunderstorms are located just inland over Mexico, especially from 18N-19N between 89W-92W. A N-S upper-level trough axis extends over the central U.S. into the northwestern Gulf of Mexico. Although drier air has built in behind these two fronts, isolated showers and storms are over SW Louisiana and could move over portions of the NW Gulf due to the upper trough. The cold front extending from Pensacola to the eastern Bay of Campeche will continue to shift across the basin, moving SE of the area late tonight. Strong to near gale force winds are expected on either side of the front, mainly over the northern waters, with some gale force winds today in the NE Gulf. High pres will build in the wake of the front this weekend with return flow expected by early next week. CARIBBEAN SEA... A strong 500 mb ridge covers the area from the SE and central Bahamas to the central Caribbean. Relatively dry air and subsidence covers the eastern and central Caribbean, where only isolated showers are found. Isolated showers are also near Trinidad and near Cuba. Latest ASCAT pass from Thursday evening shows fresh trade winds over much of the eastern and central Caribbean, with strong trades south of 15N to the coast of Colombia between 72W-77W. Moderate winds are over the western Caribbean except for the Gulf of Honduras northward to the Yucatan Channel, where slightly stronger winds are occurring. High pres NE of the area will support fresh to strong trade winds in the S central Caribbean through Sun, diminishing Sun night into early next week as the high weakens. A cold front will move into the NW Caribbean tonight, then weaken and become stationary from central Cuba to the Gulf of Honduras Sat night. Fresh to locally strong northerly winds are expected in the wake of the front tonight and Sat, highest near the Yucatan Channel. Increased showers and thunderstorms are also expected with the front in the NW Caribbean tonight into early Saturday. ATLANTIC OCEAN... Ahead of the frontal system in the NE Gulf, scattered showers are already occurring near SE Florida and the waters from 24N-27N west of 79W. Scattered showers and thunderstorms are off NE Florida north of 28N west of 79W. In the central Atlantic, a cold front extends from 31N43W to 26N47W to 25N53W, and continues as a dissipating stationary front to 25N61W. Scattered showers and thunderstorms are along and within 60 nm ahead of the front east of 46W. West of 46W, scattered showers are near the front. A secondary cold front to the north of the first front extends from 31N46W to 28N51W to 28N61W, with little to no shower activity noted. High pressure dominates the eastern subtropical Atlantic due to a 1026 mb high near 35N26W. See section above for the expected gale-force winds east of Florida. Winds and seas will increase over much of the NW waters today ahead of a cold front expected to move off the Florida peninsula tonight. The front will extend from 31N73W across the central Bahamas to Cuba Sat evening, from 31N69W to the SE Bahamas Sun evening, then stall and dissipate Mon night through Tue night. Gale force southerly winds are expected ahead of the front N of 28N between 70W and the east coast of northern Florida. Numerous showers and scattered strong thunderstorms will accompany the front beginning this afternoon east of Florida. For additional information please visit http://www.hurricanes.gov/marine $$ Hagen