000 AXNT20 KNHC 150511 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 111 AM EDT Sun Apr 15 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 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...SPECIAL FEATURES... A strong cold front is about midway on its SE trek across the Gulf of Mexico. High pressure building behind the front is supporting gale-force winds S of 21N W of 95W, and strong to near gale-force winds elsewhere behind the front. Seas of 10 to 15 ft cover the Gulf south of 27N and W of the front as confirmed by buoys 42002 and 42055. Winds and seas will gradually diminish later this morning as the front shifts farther eastward and the high pressure builds into the western Gulf. For more details please refer to the High Seas Forecast under AWIPS/WMO headers HSFAT2/FZNT02 KNHC. The aforementioned cold front will approach the southeastern United States Sunday, with increasing southerly flow ahead of the front over the Bahamas and offshore waters east of Florida. The front will reach the Atlantic waters Sunday night, with gale force winds developing north of 30N between 76W and 78W as the front moves east. The winds will then diminish below gale force through early Monday. For more details please refer to the High Seas Forecast under AWIPS/WMO headers HSFAT2/FZNT02 KNHC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of western Africa near 10N14W to 05N19W. The ITCZ continues from 05N19W to 02N30W to 02N50W. Scattered moderate convection is observed within 120 nm of the monsoon trough and ITCZ axis between 15W and 45W. ...DISCUSSION... GULF OF MEXICO... A strong cold front extends from 30N89W to 25N92W to 18N94W. Numerous moderate convection with thunderstorms are within 180 nm E of the front N of 26N. Scattered thunderstorms are also beginning to develop along a surface trough that is well ahead of the front, with the trough axis extending from 25N88W to 17N91W. Recent scatterometer data indicates mainly fresh to locally strong SE winds preceding this front. Gale force northerly winds are occurring W of the front S of 21N. Please refer to the special features section for more details. Strong to near gale-force northerly winds are occurring elsewhere behind the front. The cold front will continue to move SE across the Gulf through Sunday night, moving SE of the area on Monday, with the winds and seas behind the front gradually diminishing. High pressure will build over the northern Gulf early next week and will become centered over the NE Gulf by Tue. This will result in fresh to strong return flow developing over the western Gulf. CARIBBEAN SEA... Ridging north of the region is supporting fresh to locally strong winds over the Gulf of Honduras and much of the central Caribbean. Mainly moderate to fresh trades are occurring elsewhere. The ridge will persist into Sunday night over the western Atlantic, which will allow these conditions to prevail through that time. The ridge will shift east on Monday, which will cause the stronger winds to become confined mainly to the NE coast of Colombia until the middle of the upcoming week. A cold front crossing the Gulf of Mexico will reach the NW Caribbean Sunday night, and will then reach from eastern Cuba to Honduras Monday night before dissipating. Fresh to locally strong NE winds are expected behind the front before the front dissipates. ATLANTIC OCEAN... Mainly moderate to locally fresh winds cover the western Atlantic this morning as high pressure of 1031 mb centered near 33N57W dominates the region. SE to S winds will increase to fresh to strong W of 75W later this morning ahead of a cold front crossing the eastern Gulf of Mexico. The winds will then increase to strong to near gale force ahead of the front this afternoon as the front reaches the Florida peninsula. Winds to gale force are possible Sun night north of 30N between 76W and 78W as the front moves through the region. Please refer to the special features section for more details on this gale. The front will reach from 31N75W to south Florida before daybreak Monday, then from 31N70W to central Cuba by Mon night. Winds will diminish through late Tuesday as the southern portion of the front begins to stall out as it reaches from Bermuda to the southern Bahamas. High pressure will build along 28N in the wake of the front as the front weakens from 31N60W to the southern Bahamas Wednesday, maintaining generally light winds and modest seas north of 25N, and moderate trades south of 25N, with pulses of fresh to strong trades off Hispaniola. A weakening stationary front extends from 31N48W to 26N63W. Scattered showers are within 120 nm of either side of the front E of 55W. This front will gradually dissipate through tonight. Farther east, a 1028 mb high centered near 28N43W is maintaining light winds north of 20N, with moderate to fresh trade winds south of 20N. NE to E swell of 7 to 9 ft persists south of 20N as well, as noted in recent altimeter satellite passes, reaching as far west as the Windward Islands. For additional information please visit http://www.hurricanes.gov/marine $$ Latto