000 AXPZ20 KNHC 221545 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Numerous moderate to strong convection extends along the offshore waters of Nayarit to Guerrero associated with the remnants of Grace, currently centered near 18N105W. Aside from strong winds and low visibility, rough seas are expected in that region as well. Environmental conditions are forecast to be conducive for development, and a tropical depression is likely to form within the next day or so 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 2 days. Refer to the National Hurricane Center Tropical Weather Outlook for more details. ...TROPICAL WAVES... A tropical wave extends from 01N to 15N with axis near 107W, moving W at 10 to 15 kt. Numerous moderate isolated strong convection is from 10N to 15N between 100W and 107W. A tropical wave extends from 01N to 19N with axis near 121W, moving W at 10 to 15 kt. Scattered showers are noted along 13N, where the wave meets the monsoon trough. A tropical wave extends from 02N to 18N with axis near 138W, moving W at 10 to 15 kt. Scattered moderate convection is from 08N to 12N and W of 132W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N86W to 14N100W to 13N120W to 12N140W. Aside from the convection described in the Tropical Waves section above, scattered moderate convection from 07N to 17N between 86W and 108W, and from 08N to 14N and W of 120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate to fresh NW to N winds are over the offshore waters of Baja California to the entrance of the Gulf of California. Recent scatterometer data also show moderate to fresh SE winds across the offshore waters of Guerrero and Michoacan. Seas in these areas remain between 5 to 7 ft in SW swell. Otherwise, a surface trough supports moderate to fresh S to SW winds in the northern Gulf of California with seas to 4 ft. Winds across the Baja California and SW Mexico offshore waters will continue increasing today as the remnants of Grace move westward across the eastern Pacific Ocean. There is a high chance of tropical cyclone development 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 today through Tue. See the Special Features section for further details. 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. Regardless of development strong winds and building seas are expected Mon through Wed for the SW Mexico offshore waters. Otherwise, fresh to strong winds are forecast for the area of Tehuantepec Mon through Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Scattered showers and isolated thunderstorms continue across the offshore waters N of 04N, under the influence of moist monsoonal winds, and the passage of a tropical wave that moves across Panama today. 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, Ecuador and Galapagos Islands offshore waters with seas between 6 to 7 ft in SW swell. Long period SW swell will reach the region of the Galapagos tonight and the Central America coast Mon night and winds across the region will increase to fresh with seas reaching the 8-9 ft. Winds and seas are forecast to diminish early next weekend. REMAINDER OF THE AREA... Surface ridging continues over the far NW forecast waters, centered on a 1027 mb high way NW of the area. The pressure gradient between the ridge and a tropical wave with axis near 138W supports moderate N to NE winds N of 12N and W of 125W as confirmed by latest scatterometer data. Seas of 8 to 9 ft in NE swell across the region N of 27N is forecast to subside later this morning. Otherwise, moderate to fresh S to SW winds are south of the monsoon trough between 100W and 125W with seas to 9 ft in SW swell. The remnants of Grace will continue moving westward across the eastern Pacific waters while strengthening. For further information, see the Special Features section. $$ ERA