559 AXNT20 KNHC 220528 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 128 AM EDT Wed Aug 22 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 0515 UTC. ...TROPICAL WAVES... A tropical wave has moved off the African coast with axis along 23W between 05N-20N, moving westward at 10-15 kt. The wave is embedded within a very dry and stable environment inhibiting convection at this time. A central Atlantic tropical wave has its axis extending along 42W from 05N-18N, moving westward at 10-15 kt. This wave is also embedded within a very dry and stable environment caused by Saharan Air Layer outbreak migrating westward across the central and eastern Atlantic. Isolated showers are noted within 75 nm either side of the wave axis along 11N. A tropical wave has entered the eastern Caribbean with axis extending along 62W between 07N-19N, moving westward near 10-15 kt. No significant convection is observed with this wave at this time. A central Caribbean tropical wave has been introduced to this map after analyzing satellite imagery and latest model guidance. This wave's axis extends along 73W between 10N-20N. Scattered moderate convection is observed across Hispaniola and over the southern portion of the wave, affecting northern Colombia. A tropical wave has its axis extending across the Yucatan Peninsula along 90W and south of 21N, moving westward at near 15 kt. Scattered moderate convection is over Central America and Yucatan Peninsula between 84W-92W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the African coast near 17N16W to 10N37W. Scattered showers are noted within 75 nm north of the ITCZ boundary between 48W-50W. ...DISCUSSION... GULF OF MEXICO... Weak ridging extends across the northern Gulf of Mexico along 26N anchored by a 1019 mb high centered near 26N92W. This is maintaining light to gentle breezes and 1 to 3 ft seas. Gentle to moderate easterly flow is noted elsewhere south of the ridge. Scattered showers and thunderstorms are observed over the far southwest section of the gulf in association with the Yucatan Peninsula's tropical wave. Refer to the section above for details. Expect for this convective activity to remain active through the night. High pressure ridging will remain across the northern gulf waters, with the associated gradient producing gentle to moderate anticyclonic flow through Thu. CARIBBEAN SEA... Two tropical waves are moving across the basin. Refer to the section above for details. An upper level trough extends across the west Caribbean enhancing convection across Cuba and adjacent waters north of 18N and west of 75W. The pressure gradient across the area will maintain fresh to strong winds over the south central Caribbean off the coast of Colombia and across the Gulf of Venezuela through Thursday. Moderate to fresh trades will continue elsewhere through this period also. Expect for the tropical waves to continue moving west enhancing convection. Little change is expected elsewhere. ATLANTIC OCEAN... Over the western Atlantic, a surface trough is analyzed from near 28N78W to 25N79W. Scattered showers are noted near this trough affecting the northern Bahamas. Two tropical waves are moving across the basin. Refer to the section above for details. Another trough extends from 31N45W to 25N52W. A 1025 mb high center is analyzed north of 31N and extends a ridge across the remainder of the basin. The trough extending across the central Bahamas will continue westward through this evening. The aforementioned shower and thunderstorm activity is forecast to persist through mid-week. Saharan dust and associated dry air, as also mentioned above under Tropical Waves, is noted mainly east of about 60W on GOES-16 Saharan Air Layer animation is inhibiting convection from developing across the eastern and central Atlantic waters. For additional information please visit http://www.hurricanes.gov/marine $$ ERA