000 AXPZ20 KNHC 220239 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Aug 22 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... The remnants of Grace continue to move westward over west- central Mexico tonight. Numerous heavy showers and tstms associated with it are across the offshore waters from Nayarit to just north of Acapulco with seas ranging from 5 to 10 ft along the coastal waters. Strong winds and low visibility is expected in that region as well. By Sun afternoon, the remnants of Grace are forecast to emerge over the eastern Pacific Ocean off the west-central coast of Mexico. 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 of this system within the next 5 days. Refer to the National Hurricane Center Tropical Weather Outlook for more details. ...TROPICAL WAVES... A tropical wave extends from 05N to 17N with axis near 105W, moving W at 5 to 10 kt. Scattered moderate isolated strong convection is from 08N to 15N between 97W and 108W. A tropical wave extends from 05N to 18N with axis near 118W, moving W at 5 to 10 kt. Scattered moderate convection is from 10N to 15N between 112W and 122W. A tropical wave extends from 05N to 18N with axis near 134W, moving W at 10 to 15 kt. Scattered moderate convection is from 09N to 13N between 132W and 138W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 16N106W to low pres near 10N125W 1008 mb to 13N140W. Aside from the convection described in the Tropical Waves section above, scattered moderate convection prevails from 05N to 18N between 82W and 105W, and from 07N to 13N between 112W and 132W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the section above for details on the Special Feature system that will develop from the remnants of Grace. 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 these areas remain between 5 to 7 ft. Moderate S to SW winds continue in the northern Gulf of California being supported by a surface trough. Light to gentle variable winds prevail elsewhere. Similar conditions are forecast to remain in place through this evening. By tonight, winds across the Baja California and SW Mexico offshore waters will increase to moderate to fresh ahead of the remnants of Grace. The remnants will emerge over the eastern Pacific Ocean off the west-central coast of Mexico on Sun afternoon. Regardless of development, strong winds and building seas will affect the offshore waters of Colima, Nayarit, and Baja California Sur from 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 05N, under the influence of moist monsoonal winds aided by Grace over SE 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 between 6 to 8 ft 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 1030 mb high near 44N149W. 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 15N and W of 125W. Seas of 5 to 7 ft in NE swell prevail across this area. Elsewhere, moderate to fresh SW winds are observed S of the monsoon trough with seas in the 8 to 10 ft range. Northerly swell will continue to propagate across the north- central waters and subside tonight. 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. $$ Ramos