000 AXNT20 KNHC 140509 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 109 AM EDT Sat Apr 14 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 will cross the Gulf of Mexico beginning later this morning, and will move SE today through Sunday night over the Gulf basin. High pressure building behind the front will support gale force northerly winds S of 24N over the SW Gulf behind the cold front starting this afternoon and continuing until midday Sunday. 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 on Sunday, with increasing southerly flow ahead of the front over the Bahamas and offshore waters E of Florida. The front will reach the Atlantic waters Sunday night, with gale-force winds developing just E of the front N of 30N as the front moves E. Winds will decrease below gale-force over the discussion waters on 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 09N13W to 04N21W. The ITCZ continues from 04N21W to 03N35W to 00N50W. Scattered moderate isolated strong convection is observed from 02N to 07N between 09W and 29W. Isolated moderate convection is from 01N to 06N between 29W and 48W. ...DISCUSSION... GULF OF MEXICO... Southerly flow prevails over the Gulf basin between western Atlantic high pressure and Low pressure over Texas. The surface winds are strongest over the northwestern waters, where buoys and ships continue to report 20-25 kt winds. The highest seas are nearing 8 ft off the Texas and western Louisiana coasts this evening as suggested by three different buoys now reporting 7 ft in the area. Seas are notably lower over the eastern Gulf waters due to the lighter winds and limited fetch. The only notable convection over the Gulf this morning are isolated thunderstorms off the western tip of Cuba and just offshore NW Texas ahead of a developing pre-frontal trough. A cold front is expected to move over the northwestern waters later this morning and is expected to sweep across the entire area by Sunday night. Numerous showers and thunderstorms are expected just ahead of this front as it crosses the Gulf. Gale force winds are also forecast behind the front over the SW Gulf for a portion of this weekend, with strong northerly winds expected elsewhere over the basin in the wake of the front. Please refer to the Special Features section for more details on this gale. CARIBBEAN SEA... Fairly quiet weather conditions are occurring over the Caribbean Sea tonight, with only the typical patches of clouds and embedded showers moving westward across the region. The showers appear more concentrated over the eastern Caribbean, generally north of 13N and east of 70W. Moderate to fresh tradewinds cover the majority of the Caribbean, except strong winds near the coast of Colombia and Venezuela, and the Gulf of Honduras. Seas to 8 ft are possible early this morning under these areas of strong winds, with seas possibly reaching 10 ft later this morning north of the Colombia coast. The areal coverage of fresh to strong trades will expand today as high pressure over the Atlantic strengthens, and a cold front approaches the NW Caribbean from the Gulf of Mexico. As a result, seas greater than 8 ft may cover much of the S Central Caribbean by tonight. The front is expected to reach the NW Caribbean on Sunday, with fresh to strong northerly winds behind the front. Scattered to numerous showers and thunderstorms will be possible just ahead of the front through Monday. ATLANTIC OCEAN... A stationary front extends from 31N52W to 27N61W. Scattered showers and isolated thunderstorms are within 120 nm of either side of the frontal boundary. A surface trough, formerly the tail end of the front to its east, is now oriented from 29N69W to 26N68W. Scattered showers and isolated thunderstorms are from 27N to 31N between 65W and 71W. Fresh winds are on the northern portion of the trough axis due to the pressure gradient caused in part by high pressure to its north. Mainly moderate to fresh winds cover the remainder of the central and western Atlantic. Farther east, high pressure of 1029 mb centered near 28N36W dominates the eastern Atlantic with generally fair weather. Latest scatterometer data indicates fresh to strong NE trades to the south of the high between the Cabo Verde Islands and 40W, which is supporting seas of 8 to 9 ft. A cold front is forecast to approach the southeastern United States this weekend, with strong to near gale-force southerly winds expected to develop well ahead of the front to the north of the Bahamas early Sunday. Then, winds will briefly increase to gale- force Sunday night just ahead of the cold front N of 30N. Numerous showers and thunderstorms will precede the front Sunday night into Monday over the Bahamas and offshore waters east of Florida. Please refer to the special features section for more details. For additional information please visit http://www.hurricanes.gov/marine $$ Latto