000 AXNT20 KNHC 180457 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Thu May 18 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 0000 UTC surface analysis and satellite imagery through 0430 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 21.5W, from 00N to 11N. Westward motion is approximately 5 knots due to slow 700 mb winds, and this slow forward motion is expected to continue over the next couple of days. Scattered moderate convection is from 04N to 08N between 17W and 25W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from 10N14W to 05N20W. The ITCZ extends from 04N24W to 02N37W to the coast of far NE Brazil near 03N51W. Scattered moderate convection associated with the ITCZ is from 02N to 06N between 42W and 45W. GULF OF MEXICO... The frontal boundary in the north-central Gulf has dissipated as of 0300 UTC. Weak high pressure of 1011 mb is located near 23N94W in the southwest Gulf. Light winds prevail across the Gulf, with seas of 1-3 ft. Gentle to moderate N winds are noted within 60 nm of the coast of the Yucatan Peninsula. For the forecast, weak high pressure will continue to dominate the weather pattern across the Gulf region through the upcoming weekend producing mainly light to gentle winds and slight seas. However, winds and seas could be higher near showers and thunderstorms. Gentle to moderate NE to E winds are forecast at night near and NW of the Yucatan Peninsula through Thu night, increasing to moderate to fresh speeds Fri night through Sun night. CARIBBEAN SEA... Light to gentle trades are found over the NW Caribbean, with gentle to moderate trades elsewhere. Seas are 2-4 ft across most of the basin, increasing to locally 5 ft in the south-central Caribbean. For the forecast, a ridge axis across the central Bahamas tonight is producing a very weak pressure gradient across the Caribbean Basin. Gentle to moderate trades and slight to moderate seas are expected over the east and central Caribbean while light to gentle winds and slight seas will prevail in the NW Caribbean through Thu. Winds will increase to moderate to fresh speeds across the south-central Caribbean, including the Gulf of Venezuela Thu night through Sat night as high pressure builds modestly N of the region. ATLANTIC OCEAN... 1014 mb high pressure was centered near 24N75W at 0000 UTC, though more recent data suggests this high pressure has degenerated into a ridge axis. The tropical Atlantic is quite quiet. The Azores High is supporting moderate to fresh trades over the northeastern discussion waters. Trades are gentle to moderate elsewhere, except in the northwestern waters where winds are light. Seas are 2-4 ft west of 60W, and 4-7 ft elsewhere in open waters. For the forecast west of 55W, the ridge will build modestly across the regional waters late Thu through the weekend. Low pressure is forecast to develop along a frontal boundary just off the SE U.S. late Thu, then move toward Cape Hatteras by late Fri, with strong winds and rough seas expected to remain north of 31N. A surface trough is also expected to develop over the NE waters by Thu night. A weak low may develop along the trough axis late on Fri. Expect increasing winds and building seas to 8 ft across the N waters between 60W and 70W on Fri as a strong high pressure briefly builds across the region between the two above mentioned lows. $$ Mahoney