000 AXPZ20 KNHC 210225 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sat Aug 21 2021 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...SPECIAL FEATURES... Hurricane Grace near 20.7N 96.3W 967 mb at 11 PM EDT moving W at 9 kt. Maximum sustained winds 85 kt gusts 105 kt. Grace will move inland and weaken to a tropical storm near 20.3N 97.9W Sat morning, inland to 20.0N 100.9W Sat evening, and dissipate Sun morning. Grace's remnants are expected to continue moving westward and emerge over the eastern Pacific Ocean off the west- central coast of Mexico by Sunday afternoon. Environmental conditions are forecast to be conducive for development, and a tropical depression is likely to form by early next week while the system moves westward away from the coast of Mexico. There is a high chance of tropical cyclone formation within the next 5 days. For further details see the National Hurricane Center Tropical Weather Outlook. ...TROPICAL WAVES... A tropical wave extends from 02N to 15N with axis near 100W, moving W at 5 to 10 kt. Scattered moderate convection is from 08N to 14N between 96W and 105W. A tropical wave extends from 06N to 19N with axis near 115W, moving W at 5 to 10 kt. Scattered moderate convection is from 08N to 17N between 107W and 120W. A tropical wave extends from 05N to 17N with axis near 128W, moving W at 10 kt. Scattered moderate isolated strong convection is from 08N TO 13N between 120W and 131W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 17N104W to 11N120W to 13N130W to 14N136W. Aside from the convection described in the Tropical Waves section, scattered moderate to strong convection is N of 04N E of 95W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak pressure gradient across the region continues to support light to gentle NW to N winds along the Baja California offshore waters with seas ranging 5 to 7 ft. Light to gentle variable winds are elsewhere from Tehuantepec to the central Gulf of California with seas to 6 ft, except for 1 to 3 ft in the Gulf. A surface trough along the northern Gulf of California supports moderate S to SW winds with seas 2 to 3 ft in that area. Similar conditions are forecast to remain in place through Sat. On Sat evening, winds across the Baja and SW Mexico offshore waters will increase to moderate to fresh ahead of the remnant low of Hurricane Grace, currently moving westward across the southwest Gulf of Mexico. Grace is forecast to move inland across central Mexico early tonight, and weaken as it continues westward across the mountainous terrain of central Mexico, then emerge over the eastern Pacific Ocean off the west-central coast of Mexico early on Sun. Environmental conditions are forecast to be conducive for development, and a tropical depression is likely to form late this weekend or early next week while the system moves westward away from the coast of Mexico. Regardless of development, strong winds and building seas will affect the offshore waters of Colima, Nayarit, and Baja California Sur Sun through Tue. Another area of low pressure is forecast to form off of the southwest coast of Mexico late Tue or Wed of next week. Environmental conditions are expected to be conducive for some gradual development thereafter while the system moves west- northwestward near or just offshore the southwestern coast of Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Scattered showers and thunderstorms prevail across the offshore waters N of 04N, under the influence of moist monsoonal winds aided by Hurricane Grace across the Gulf of Mexico, and the passage of tropical waves. Light to gentle variable winds with seas to 6 ft are noted N of the monsoon trough while moderate to locally fresh S to SW winds are across the Costa Rica, Panama, Ecuador and Galapagos Islands offshore waters with seas 7 to 8 ft in long-period SW swell. Similar marine conditions will prevail through early next week, except for moderate to fresh NE to E winds forecast to pulse off the Gulf of Papagayo at night. REMAINDER OF THE AREA... Surface ridging continues over the NW forecast waters, centered on a 1035 mb high near 45N149W. The pressure gradient between the ridge, and the Post-Tropical remnants of Linda to the west, near 20N 145W at 1800 UTC, and deep layered troughing along 124W, continue to support moderate N to NE winds N of 18N and W of 124W. Seas of 6 to 9 ft in NE swell prevail across this area. Elsewhere, moderate to fresh SW winds are observed S of the monsoon trough with seas to 8 ft. Northerly swell will continue to propagate across the north- central waters and subside Sat night. Seas will be in the 8-9 ft range in that region. Otherwise, the ridge centered well NW of the area will maintain a modest gradient across the western waters, with moderate N to NE winds persisting north of the monsoon trough and west of 125W. To the east, the remnants of current Hurricane Grace are forecast to emerge over the eastern Pacific Ocean off the west- central coast of Mexico on Sun. Environmental conditions are forecast to be conducive for development, and a tropical depression is likely to form late this weekend or early next week while the system moves westward away from the coast of Mexico. $$ Ramos