000 AXPZ20 KNHC 212226 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Oct 21 2020 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2150 UTC. ...TROPICAL WAVES... A tropical wave has been analyzed along 105/106W from 15N north. Satellite imagery and model diagnostic suggest the wave location to be there. The convection along the wave axis is limited, but an area of scattered moderate convection is noted near the intersection of the monsoon trough. A tropical wave is analyzed along 123W from 08N to 18N, moving W at 10 to 15 kt. An associated 1009 mb low pressure center is located near 14N119W and moving in tandem with the wave. Scattered moderate to isolated strong convection is noted within 200 nm SW and 180 nm in the NW quadrant. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N86W to a 1009 mb low pres near 08N101W to second low pres 1009 mb near 14N119W to 11N134W. The ITCZ continues from 11N134W to beyond 10N140W. Scattered moderate convection is noted from 07N to 11N along the coast of Costa Rica, from 06N-12N between 108W-111W, and from 08N-14N along the transition from the monsoon trough to the ITCZ, west of 130W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between the high pressure to the west of Baja California and a trough along the Gulf of Baja California has relaxed supporting light to gently NW winds across the offshore waters of Baja California. Farther south, including the Gulf of California, except for a small area of fresh winds across the Gulf of Tehuantepec, gentle to moderate breezes persist. Seas offshore of Baja are generally in the 4 to 6 ft range in mixed N and SW swell, 5-6 ft south of Cabo San Lucas, and 3 ft or less across all but the mouth of the Gulf of California. Winds will remain modestly overnight offshore of Baja California as the ridge shifts westward, with seas subsiding by a foot or so through this evening. Mostly gentle to moderate breezes and seas 5 ft or less will persist elsewhere. Winds will diminish further through the end of the week across the offshore Baja California waters with seas subsiding to 4 ft by Thu and Fri. However, strong northerly winds offshore of southern California will push a new N swell across the outer waters tonight through the Fri and raise seas across the offshore waters of Baja California Norte to 6-8 ft by Fri. Gulf of Tehuantepec: ASCAT indicates moderate to locally fresh northerly winds across the Gulf of Tehuantepec with seas up to 9 ft. Fresh N winds are expected to remain near 20 to 25 kt Through Thu, and extend only 90-120 nm downwind in a relatively narrow plume. Nocturnal pulses of 25-30 kt will return into the weekend. Seas will peak this evening up to 9 ft and remain below 8 ft through the weekend. Looking ahead, the first strong cold front of the season will move across northern Mexico and much of the Gulf of California Sun night through Mon. This will bring strong westerly gap winds across north and central portions of the Gulf late Sun through Mon evening, before strong northerly winds begin to spread southward across the basin Mon night and Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to locally fresh SW winds prevail south of the monsoon trough south of 06N, east of 99W. Seas south of Costa Rica and Panama are 6 to 8 feet in mixed SW swell. These conditions will continue with little change overnight before winds subside slightly and long period SW swell begins to slowly fade across the region through Thu. Broad low pressure across the southwest Caribbean is aiding in producing an area of fresh S to SW winds south of Panama and Costa Rica, and is also helping to produce an active weather across these eastern waters and Central America east of 86W. This active weather is expected to continue through tonight before beginning to shift northward over land and diminish over water as elongated low pressure across the western Caribbean lifts NW into the southern Gulf of Mexico. REMAINDER OF THE AREA... A 1030 mb high pressure near 47N137W extends a ridge SE to near 19N128W, and is supporting moderate to fresh NE to E winds from roughly 13N to 27N mainly east of 140W. Seas are generally 6-8 ft across this zone. Expect little change in this pattern through the end of the week. Low pressure of 1009 mb along the monsoon trough near 14N119W follows a tropical wave along 123W. This low will shift WNW over the next several days and move south of the ridge. As this occurs, the pressure gradient across the N semicircle of the low will produce a zone of winds around 20 kt, and occasionally to 25 kt. $$ MTorres