000 AXNT20 KNHC 221153 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 753 AM EDT Fri Jun 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 32W from 03N to 18N, moving W at 15 kt. Abundant cloudiness surrounds the wave's axis but convection is limited. The axis of a tropical wave is near 50W from 02N to 18N, moving W at about 15 knots. Scattered moderate convection is noted from 05N to 09N between 45W and 53W. This wave will pass west of 55W late today, move across the eastern Caribbean Sat, the central Caribbean Sun, and through the western Caribbean early next week. The axis of a tropical wave is near 64W from 06N to 20N, moving W at about 10 knots. Scattered moderate convection associated to this wave is noted from 13N to 17N between 60W and 64W, and it is still affecting the Lesser Antilles. This wave will reach the central Caribbean later today, then across the western Caribbean into Central America through Sun. Moisture associated with this wave will increase the likelihood of showers and isolated tstms over Puerto Rico and the Virgin Islands today, then across Dominican Republic tonight into Sat. The axis of a tropical wave is near 77W from 09N to 21N. Convection is limited. This wave will continue through western Caribbean through late today. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the coast of western Africa near 16N16W to 5N27W. The ITCZ continues from 5N27W to 04N50W. Outside of the convection associated with the tropical waves, isolated moderate convection is from 02N to 08N between 32W and 58W. ...DISCUSSION... GULF OF MEXICO... A 1011 mb low pressure centered over NE Mexico near 25N100W continues to produce a large area of showers NE Mexico. The low will continue to weaken today, with associated convection decreasing. Weak ridging will persist from the southeast Gulf to Texas through early next week. SE return flow will increase slightly over the western Gulf between the ridge and weak low pressure over northern Mexico. A surface trough will develop in the Yucatan Peninsula each afternoon, then move westward across the SW Gulf during the overnight hours, accompanied by fresh to occasionally strong east to southeast winds. CARIBBEAN SEA... A tropical wave is moving across the western Caribbean. Another tropical wave is over the eastern Caribbean affecting the Lesser Antilles. Please, see Tropical Waves section for details. Expect increasing showers and isolated thunderstorms in association with the passage of these tropical waves. High pressure N of area is forecast to strengthen over the next couple of days while moving westward. As a result, the trade winds over the south-central Caribbean will strengthen and expand in areal coverage across the basin through early next week. Winds could reach near gale force along the coast of Colombia by Sun night. Fresh to strong winds will affect the Gulf of Honduras each night beginning tonight through Mon night. ATLANTIC OCEAN... An upper-level trough extends from a cyclonic circulation centered near 26N66W to eastern Cuba. Scattered showers and tstms are noted on the SE semicircle of the low affecting mainly the waters from 21N to 26N between 63W and 71W. High pressure of 1030 mb centered near 34N37W extends a ridge westward across the forecast area. Fresh trades are noted along the southern periphery of the ridge, but mainly between 40W-70W. This high pressure will slowly shift westward through Sat night, then remain nearly stationary near 30N55W through Tue. The tightening pressure gradient that results over the central Atlantic will support fresh to strong trade winds and seas of 8-10 ft E of the Lesser Antilles to about 45W by early Sat morning. These marine conditions will persist on Sun. For additional information please visit http://www.hurricanes.gov/marine $$ GR