000 AXNT20 KNHC 242310 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 710 PM EDT Sat Jun 24 2017 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. ...TROPICAL WAVES... An eastern Atlantic tropical wave has an axis that extends from 18N34W to 05N38W, moving westward at 15 to 20 kt. This wave is embedded in a large 700 mb trough, with Saharan dust across the wave environment north of 10N. Isolated moderate convection is within 120 nm of either side of the wave axis south of 10N. A central Atlantic tropical wave has an axis that extends from 17N54W to 06N57W, moving westward at 15 to 20 kt. This wave embedded in broad 700mb troughing, with some turning evident in satellite imagery. Scattered moderate convection is from 09N to 14N between 55W and 59W. A tropical wave is over the east-central Caribbean with an axis extending from 18N70W to 08N71W, moving westward at 15 kt. This wave is indicated by 700 mb troughing in model field data. Dry air an subsidence over the northern portion of the wave is inhibiting convection over the Caribbean, with convection mainly confined to northern Venezuela. ...MONSOON TROUGH/ITCZ... The Monsoon Trough extends from the Africa coast near 07N12W to 07N20W. The Intertropical Convergence Zone axis begins near 07N20W and continues to 08N32W to 05N37W, then resumes W of a tropical wave near 04N39W and continues to 05N52W. Aside from the convection associated with the tropical waves, scattered moderate and isolated strong convection is within 180 nm either side of the convergence axis. ...DISCUSSION... GULF OF MEXICO... High pressure over the western Atlantic has a ridge axis that extends across the northern Gulf to about 90W along about 28N, supporting moderate southeast winds across the southern half of the Gulf. The only exception is light winds in the vicinity of the ridge axis over the northeastern Gulf. A vigorous upper low over the SW Gulf and a surface trough along the Yucatan Peninsula supports scattered thunderstorms mainly south of 24N, between 87W and 92W. During the next 24 hours a weak frontal boundary over the southern United States will drift into the northern Gulf coast, increasing chances for showers and thunderstorms over the northern Gulf. The upper low will move west toward central Mexico. CARIBBEAN SEA... The Caribbean is nearly devoid of deep convection this evening, as mid to upper level dry air has spread across much of the basin. Mainly moderate to fresh trades prevail in the Caribbean, except light winds over the southwest Caribbean south of 11N. A tropical wave is along 70W. Please refer to the tropical waves section for more details. By Sunday afternoon, a stronger Atlantic tropical wave will reach the Lesser Antilles, with increased showers and thunderstorms. ...HISPANIOLA... widely scattered showers will affect the southern portion of the island through Sunday as a tropical wave passes to the south. ATLANTIC OCEAN... A pair of tropical waves are crossing the tropical north Atlantic waters. Please refer to the tropical waves section for more details. A weak surface trough lacking convection extends from 28N59W to 24N63W. Another weak surface trough, which is the reflection of an upper low aloft, extends from 30N48W to 26N51W. This trough also lacks deep convection. High pressure centered north of the discussion area in the east-central Atlantic has a ridge axis that extends west-southwestward to northern Florida, and dominates the remainder of the tropical Atlantic waters. For additional information please visit http://www.hurricanes.gov/marine $$ Mundell