000 AXNT20 KNHC 191738 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 138 PM EDT Thu Apr 19 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough along the coast of Africa near 10N14W extends southwestward to 06N16W and then westward to 03N22W. The ITCZ continues weatward from 03N22W to 01N51W. Scattered moderate showers and isolated thunderstorms were occurring within 90 nm either side of the ITCZ and monsoon trough. ...DISCUSSION... GULF OF MEXICO... A ridge extending westward from central Florida to the northeastern coast of Mexico will shift eastward ahead of a cold front moving southward over the northern and northwestern Gulf, with the front becoming stationary from south Forida to south Texas by Friday morning. Light to moderate E to SE winds continue over most of the Gulf, with 1 to 3 ft seas in the northeast Gulf and 2 to 4 ft seas elsewhere. Visibility will remain unrestricted across the Gulf, and no showers or thunderstorms expected into Friday morning. Fresh to occasionally strong northerly flow behind the front will spread southward over the northern Gulf N or 27N into this evening. After stalling across the central Gulf on Friday, the front will drift north over the western Gulf as a warm front by Fridat afternoon. Fresh to strong easterly winds are expected over the northeastern Gulf into Sat as high pressure builds north of the area behind the front. The front will weaken across Florida and the eastern Gulf on Sat, possible returning northward as a warm front on Sunday, ahead of another cold front that will emerge off the Texas coast late Sat night/early Sun morning. This second weak front will extend from the mouth of the Mississippi River southwestward to near Veracruz Mexico by late Sun, and from the Florida Panhandle to the northeastern Yucatan peninsula by late Monday, followed by moderate northerly winds. CARIBBEAN SEA... An upper trough over the Windward Passage is aiding the development of scattered showers and isolated thunderstorms across Puerto Rico and Hispaniola, and the adjacent Caribbean and Atlantic coastal waters. Elsewhere, fresh to strong NE to E winds persist off the coastlines of northwest Venezuela to Colombia with 8 to 10 ft seas. Otherwise, moderate winds and seas, accompanied by dry conditions persist across the basin. For the forecast, building high pressure north of the area will maintain fresh to locally strong tradewind flow along the north coast of South America today. These winds will expand northward over the south central Caribbean into the southwest Caribbean through Fri, then diminish somewhat late this weekend into early next week. Northeasterly swell will increase east of the Leewards tonight and Friday, then decay from west to east through Sun. ATLANTIC OCEAN... A weak, stationary surface trough extended from 31N61W to 25N71W. A few isolated showers were occuring along and within 60 nm of the trough. The weak trough will drift westward today, becoming diffuse this afternoon and dissiapting tonight. Moderate to fresh southerly flow is noted off the northeast coast of Florida between the ridge and lower pressure over the southeast United States. Seas are generally 3 to 5 ft in open waters. A cold front will move off the northeastern Florida coast by tonight and reach from near Bermuda to south Florida by late Fri, then stall from 26N65W to the Straits of Florida by late Sat. Remnants of the front will lift northward on Sun ahead of another cold front that will move eastward across the southeastern United States and enter the northwest waters by late Tue. Farther east, a 1032-mb high was centered near 34N38W was producing moderate to fresh trade winds over the deep tropics. Large long period northerly swell persists, with 12 to 14 ft seas covering the region north of 20N east of 50W, and 8 to 12 ft seas present north of 12N and east of 55W. For additional information please visit http://www.hurricanes.gov/marine $$ Stewart