000 AXNT20 KNHC 160005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... ...Atlantic Gale Warning... A cold front over the eastern Gulf of Mexico will move E across the west Atlantic area beginning later tonight, extending from 31N77W to 27N80W by early Mon. Gale- force winds are expected north of 26N east of the front to 74W starting late this evening, with seas ranging between 8-12 ft outside of the Bahamas. These conditions will begin to improve by late Monday morning. 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 10N13W to 04N21W. The ITCZ continues from 04N21W to 03N30W to 02N50W. Isolated moderate convection is observed from 02N to 08N between 13W and 25W, and from 00N to 03N between 43W and 51W. ...DISCUSSION... GULF OF MEXICO... Fresh to strong northerly winds follow a late season cold front that extends from 30N84W to 21N88W. A pre-frontal squall line is quickly moving east, and at 2100 UTC extended from 27N82W to 21N85W. Scattered to numerous showers and thunderstorms along with gusty winds are noted along and E of the squall line, including the Yucatan Peninsula and Channel. Seas range between 8-13 ft along and within about 300 nm W of the front, with the 13 ft observation over the central Gulf measured by buoy 42001. High pressure has built over the western Gulf behind the front, with a 1027 high center near 21N98W. The front will continue moving east across the remainder of the eastern Gulf through tonight. Winds and seas will diminish into Mon as high pressure continues to build east across the basin. The center of the high pressure ridge will reach the NE Gulf by mid week, which will help to induce fresh to strong SE return flow will over the northwest Gulf by late Tue between the ridge and lower pressure over the southern Plains. A weaker cold front is forecast to stall and dissipate over the northern Gulf Thu. CARIBBEAN SEA... Moderate to fresh easterly winds prevail across most of the basin. An earlier scatterometer passes indicated fresh to strong east winds off northeast Colombia and near the Gulf of Honduras. Seas over the south central Caribbean are likely 8 to 10 ft, with 5 to 8 ft elsewhere NE to E swell over the tropical Atlantic W of 55W has largely decayed to 6 to 8 ft. A pre-frontal trough has entered the NW Caribbean this evening and is supporting gusty winds and numerous showers with embedded thunderstorms NW of a line from 22N82W to 16N87W. The cold front currently over the southeastern Gulf will enter the northwest Caribbean later tonight, and stall from central Cuba to central Honduras late Mon, before dissipating through late Tue. Showers and thunderstorms will continue to progress SE ahead of the cold front through Mon. Strong NW winds will follow the front from the coast of Quintana Roo in the Yucatan to the Gulf of Honduras, before diminishing Mon. Elsewhere, the fresh to strong trade winds will continue to pulse near the coast over the south central Caribbean through mid week, and will expand eastward to along the coast of Venezuela by late this week. ATLANTIC OCEAN... Gale-force winds are expected to develop over the west Atlantic this evening. Please refer to the section above for more details. High pressure northeast of the area is supporting pulses of fresh to strong trade winds off Hispaniola, as noted in earlier scatterometer imagery and ship observations. The strong winds are noted mainly along the northern coast of Haiti as far west as the approaches to the Windward Passage. Strong to near gale-force southerly winds are occurring W of 75W N of 26N as the cold front over the eastern Gulf of Mexico approaches. A pre-frontal squall line has reached the waters E of NE Florida, with the lien as a whole extending from 31N81W to central Florida as of 2100 UTC. Gusty shifting winds and numerous thunderstorms will accompany this squall line as it moves east over the western Atlantic waters through Monday. The cold front will reach the E coast of Florida late tonight, then reach from 31N70W to central Cuba late Monday night. The southern portion will then stall from 25N70W to E Cuba Tuesday, with the north portion stalling from 31N60W to 25N67W on Wednesday. The entire front will then weaken and dissipate later this week. Fresh to strong winds behind the front will diminish Tuesday and Wednesday as high pressure becomes centered over the western Atlantic. Elsewhere, surface ridging prevails across the basin anchored by a 1030 mb high near 33N60W. A dissipating stationary front extends from 31N29W to 30N48W. The ridge is maintaining light winds north of 20N, with moderate to fresh trade winds south of 20N. East swell of 7 to 9 ft persists south of 20N as well E of 55W, as noted in recent altimeter satellite passes. The stationary front will dissipate tonight, and the ridge will shift east Monday ahead of a reinforcing cold front that will move into the central Atlantic region Tue. The front will slide east of 35W Wed, followed by a large area of NW swell with wave heights of 8 to 10 ft covering much of the area north of 20N and east of 45W Wed and Thu as the swell in excess of 8 ft south of 20N will subsides. For additional information please visit http://www.hurricanes.gov/marine $$ Latto