000 AXNT20 KNHC 191738 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 138 PM EDT Sat May 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 1730 UTC. ...SPECIAL FEATURES... An upper-level trough extends across the eastern Gulf of Mexico and western Caribbean, with a diffluent flow prevailing across the Florida Peninsula and western Atlantic/Caribbean mainly east of the trough's axis. This pattern is enhancing moisture across the area, with a constant transport of tropical moisture between 78W-83W. With this, numerous moderate to isolated strong convection prevails over this area. This activity is expected to continue through the weekend and early next week. ...TROPICAL WAVES... A central Atlantic tropical wave has an axis that extends from 12N51W to 00N53W, moving W at 10 to 15 kt. This wave appears as a poleward surge in low-level moisture and troughing is noticed at 700 mb. Scattered showers are within 300 nm of either side of the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Guinea near 09N13W to 04N20W. The ITCZ continues from 04N20W to 02S40W. Besides the convection associated with the tropical wave, scattered moderate convection prevails from 00N-04N and east of 30W. ...DISCUSSION GULF OF MEXICO... An upper-level trough prevails across the eastern Gulf, with axis along 85W. A diffluent flow east of the trough is bringing tropical moisture over the far east Gulf and western Atlantic waters affecting the Florida Peninsula and Florida Straits/Keys. A surface trough is depicted within this convection and extends from 27N80W to 24N80W. This activity is expected to continue through the weekend. A weak ridge axis extends across the remainder of the basin along 30N producing mainly gentle to moderate winds. The surface trough is expected move into the eastern Gulf through Sunday. The upper-level trough over the eastern Gulf will remain for several days, thus a similar wet pattern is expected through this period. CARIBBEAN SEA... An upper-level trough extends over the eastern Gulf of mexico and western Caribbean. Upper-level diffluence on the eastern side of this trough is supporting scattered to numerous moderate convection across the Caribbean waters between 76W-84W. This convection has been persistent over this area during the past couple of days, therefore, a flood threat exists for the islands affected. Scattered to numerous showers and thunderstorms are developing along and north of the monsoon trough mainly south of 12N and west of 73W. Broad high pressure over the subtropical Atlantic continues to support moderate to fresh tradewinds over most of the basin, except fresh to strong winds over the central Caribbean. Wave heights of 8 to 10 ft continue to occur over the south central Caribbean as confirmed by a recent satellite altimeter pass and current buoy data. Over the next couple of days, the upper-level trough will remain in place enhancing shower and thunderstorm activity over the western Caribbean. The surface ridging pattern over the Atlantic will persist, keeping a similar wind profile in place across the basin into early next week. ATLANTIC OCEAN... A diffluent flow aloft to the east of an upper-level trough currently over the eastern Gulf of Mexico is supporting scattered to numerous moderate convection across Florida, the Bahamas, and Atlantic waters mainly west of 76W. To the east, a 1030 mb high is centered over the central Atlantic near 33N58W. A 1029 mb high is also over the central Atlantic near 32N44W. These centers anchor a very broad ridge that spans the Atlantic waters east of Florida to the northwest African coast. A recent scatterometer pass indicates fresh to locally strong southeast winds over a portion of the Bahamas. The pressure gradient between the central Atlantic high and lower pressures in the Caribbean is producing fresh to locally strong easterly winds along the northern coast of Hispaniola and eastern Cuba. Moderate to fresh tradewinds are occurring elsewhere across the central and western Atlantic south of 27N. Gentle to moderate winds cover the central Atlantic north of 27N. Moderate to occasionally fresh northeast winds are occurring over the eastern Atlantic. The overall pattern will change little over the weekend, therefore, the chances for heavy rainfall over the Florida Peninsula and western Atlantic continue. For additional information please visit http://www.hurricanes.gov/marine $$ ERA