000 AXPZ20 KNHC 210824 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Hurricane Grace near 20.5N 97.8W 962 mb at 5 AM EDT moving W at 12 kt. Maximum sustained winds 100 kt gusts 120 kt. Grace will weaken to a tropical storm near 20.2N 99.6W this afternoon, move farther inland and weaken to a tropical depression near 20.1N 101.6W 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 101W, moving W at 5 to 10 kt. Numerous moderate isolated strong convection is from 10N to 14N between 100W and 103W. A tropical wave extends from 05N to 20N with axis near 116W, moving W at 5 to 10 kt. Scattered moderate convection is from 08N to 15N between 108W and 120W. A tropical wave extends from 03N to 18N with axis near 129W, moving W at 10 kt. Scattered moderate convection is from 08N to 12N between 120W and 130W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N85W to 10N90W to 13N96W then resumes near 16N107W and continues along 11N120W to 13N130W to 14N137W. The ITCZ begins near 14N137W and continues beyond 13N140W. Aside from the convection described in the Tropical Waves section, scattered moderate to strong convection is N of 04N E of 93W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Recent scatterometer data confirm gentle to moderate NW to N winds along the Baja California offshore waters, and SW to W winds of similar magnitude in the Guerrero and Colima offshore waters. Seas in those regions remain between 5 to 7 ft. Moderate to locally fresh S to SW winds continue in the northern Gulf of California being supported by a surface trough. Light to gentle variable winds are elsewhere. Similar conditions are forecast to remain in place through today. Tonight, winds across the Baja California and SW Mexico offshore waters will increase to moderate to fresh ahead of the remnant low of Hurricane Grace, which is expected to weaken to a tropical storm near 20.2N 99.6W this afternoon, move farther inland and weaken to a tropical depression near 20.1N 101.6W Sun morning, and dissipate Sun afternoon. The remnants of Grace will emerge over the eastern Pacific Ocean off the west-central coast of Mexico on Sun 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. 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 offshore of the coast of southern Mexico early next week. Environmental conditions are expected to be conducive for some gradual development thereafter, and a tropical depression could form by the middle of next week. The system is forecast to move generally west-northwestward near or just offshore of 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 SW 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 7 to 8 ft seas in long-period SW swell. Similar marine conditions will prevail through the middle of next week, except for moderate NE to E winds forecast to pulse off the Gulf of Papagayo through Mon. REMAINDER OF THE AREA... Surface ridging continues over the NW forecast waters, centered on a 1036 mb high near 45N150W. The pressure gradient between the ridge, and the remnants of Linda over the central Pacific continue to support moderate N to NE winds N of 20N and W of 125W. 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 through the middle of next week. 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 by Sun 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. $$ Ramos