000 AXPZ20 KNHC 102134 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Nov 10 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 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 13N88W to 10N130W. The intertropical convergence zone reaches from 10N130W to 11N135W to beyond 10N140W. Scattered moderate convection is observed from 08N to 11N between 100W and 115W. Scattered moderate to isolated strong convection is observed from 12N to 14N between 138W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad ridge extends from 1034 mb high pressure to Baja California Sur. Recent scatterometer satellite data indicate moderate to fresh NW winds off Baja California Sur and in the Gulf of California, between the ridge to west and 1007 mb low pressure over north central Mexico. Gentle to moderate winds are ongoing off Baja California Norte. Recent altimeter satellite data indicates seas of 7 to 10 ft seas off Baja California and the Revillagigedo Islands. The higher seas are due primarily to NW swell in the area. Seas are 2 to 4 ft in the northern half of the Gulf of California, and 3 to 5 in the southern Gulf of California. Farther south, recent scatterometer satellite data indicated moderate to locally fresh winds in showers activity off western Oaxaca, where a trough extends offshore from the low over central Mexico. Light to gentle breezes prevail elsewhere off southern Mexico. Seas are 4 to 6 ft primarily in SW swell. The fresh NW winds off Baja California and the Gulf of California will diminish late Wed into Thu as the ridge west of the area weakens ahead of an approaching weak cold front. Meanwhile, the NW swell off Baja California Norte will subside through Thu. Little change is expected through Sat. Looking ahead, increased winds and seas are expected off Baja California Norte has high pressure builds west of the area, followed by a new round of 8 to 10 ft swell by Mon, which will gradually diminish through mid week. Farther south, strong gap winds may start in the Gulf of Tehuantepec by late Sun as a cold front moves across the western Gulf of Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Seas of 4 to 6 ft prevail in this area, in a mix of SW cross- equatorial swell and NW swell. Moderate moderate W to NW winds will persist north of monsoon trough, which will remain roughly through the Gulf of Papagayo. SW winds will prevail across the region through the forecast period farther south, with SW winds briefly becoming fresh off Costa Rica and Panama by Fri. REMAINDER OF THE AREA... Surface ridging dominates the waters north of 15N, anchored by a 1033 mb high pressure well to the north of the area near 36N141W. An upper level low is centered near 21N140W. Divergence aloft on the southeast side of the upper low is supporting a cluster of showers and thunderstorms near 15N137W, and a surface trough along 134W from 08N to 12N. A recent scatterometer satellite pass from around 18 UTC indicated fresh to strong trade winds from 15N to 20N west of 135W, between the surface trough and the ridge to the north. Moderate trade winds prevail elsewhere west of 120W. Farther east, light NW winds persist north of the monsoon trough, with moderate to fresh SW winds to the south of the monsoon trough. Recent altimeter satellite data indicates 6 to 8 ft seas are present over much of the area north of 10N, west of 120W. This is primarily in NW swell. Mixed NW and SW swell to 8 ft is evident east of 120W. The upper low loses definition tonight as a mid/upper trough digs into the waters north of 25N and west of 130W, allowing the convection and strong winds to diminish. A weak cold front will move into the waters north of 25N west of 135W by late Wed, associated with the mid/upper trough. The front will stall and dissipate through Fri. The NW swell will subside in the meantime, although new NW swell will follow briefly follow the front Thu across the waters north of 25N and west of 135W. By Fri, the ridge will be in place again across the waters north of 20N, supporting moderate to fresh trade winds between 10N and 20N west of 120W. Moderate to fresh SW flow will persist into the monsoon trough in the waters east of 120W. SW will increase east of 120W, maintaining seas to 9 ft in an area from 05N to 15N between 100W and 120W. Looking ahead, there is good agreement among global models an area of low pressure will form by late Sat into early Sun along the monsoon trough just outside of the Mexican offshore waters off Guerrero and Michoacan. The low is expected to drift slowly WNW to the south of Socorro Island through Tue, but there is some uncertainty regarding how strong the low pressure will be. The official forecast is a model consensus showing fresh to strong winds near this low by Tue. Farther north, a new round of northerly swell in excess of 8 ft can be expecte by Sun in the waters north of 25N. $$ Christensen