662 AXNT20 KNHC 160956 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Tue May 16 2023 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0950 UTC. ...TROPICAL WAVES... An eastern Atlantic tropical wave is analyzed along 15W, from 02N to 12N, moving westward at 10 to 15 knots. Scattered moderate convection is noted west of the wave from 03N to 06N, between 16W and 24W. ...MONSOON TROUGH/ITCZ... The monsoon trough is confined to the African continent. The ITCZ extends from 05N22W to 01N40W to 06N57W. Isolated moderate convection is observed from 04N to 06N between 30W and 42W, and from 05N to 08N between 46W and 54W. ...GULF OF MEXICO... A north-to-south oriented surface trough is analyzed in the central Gulf of Mexico along 90W. A few thunderstorms are observed in the vicinity of this feature. Otherwise, weak high pressure dominates the basin with light to gentle winds and slight seas across the basin. The Popocatepetl volcano is producing volcanic ash that may be reaching the SW Gulf of Mexico. While the latest advisory suggests the ashfall is now confined inland and visibility doesn't appear to be degraded significantly over the Gulf, any remaining pumice rafts are hazardous to salt water intakes and should be avoided. For the forecast, weak high pressure will dominate the weather pattern across the Gulf waters this week producing mainly light to gentle winds and slight seas. Gentle to moderate westerly winds are expected over the northern Gulf Wed and Wed night as a cold front approaches the area. Gentle to moderate NE to E winds are forecast at night near and NW of the Yucatan Peninsula through Sat night. ...CARIBBEAN SEA... The eastern Pacific monsoon trough extends across the northern coast of Panama. Scattered moderate convection is observed from 09N to 12N between 79W and 82W. The gradient between subtropical high pressure and lower pressure in the vicinity of the monsoon trough is supporting moderate to fresh trade winds in the central and eastern Caribbean. These winds are building 4-6 ft seas. Gentle winds and slight seas are observed in the NW Caribbean. For the forecast, fresh trade winds over the south central and SE Caribbean will decrease to moderate tonight before regenerating Thu-Fri. Light to gentle winds in the NW Caribbean will persist through the week. ...ATLANTIC OCEAN... A surface trough is analyzed from 30N57W to the NW Bahamas. Isolated moderate convection is observed from 22N to 28N between 62W and 72W. Otherwise, high pressure dominates the western Atlantic with gentle to moderate winds and slight to moderate seas. In the eastern Atlantic, the gradient between high pressure near the Azores and lower pressure over NW Africa is supporting fresh NE winds and 6-8 ft seas. In the tropical Atlantic south of 20N, moderate to fresh trade winds and 6-9 ft seas are observed. For the forecast west of 55W, gentle to moderate winds will persist across the majority of the western Atlantic through the week. A low pressure system and associated frontal boundaries will move over the western subtropical Atlantic late Tue. By Thu, high pressure will build NW of this feature and the gradient will generate strong easterly winds and build seas of 8-12 ft north of 31N, off the coast of South Carolina. $$ Flynn