000 AXPZ20 KNHC 061600 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Sep 6 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 1530 UTC. ...SPECIAL FEATURES... Low pressure of 1009 mb is located along the monsoon trough near 16.6N 105W, or a couple of hundred miles south-southeast of Manzanillo, Mexico moving northwest near 10 kt. Recent and current satellite imagery show disorganized scattered moderate convection from 13N to 20N between 102W to 109W. Environmental conditions appear conducive for gradual development of this system during the next few days, and a tropical depression is likely to form by midweek while it moves west-northwestward or northwestward at 5 to 10 mph, just offshore the coast of Mexico. This system has a medium chance of becoming a tropical cyclone during the next 48 hours and a high chance in the next 5 days. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...TROPICAL WAVES... The southern part of the axis of a Caribbean Sea tropical wave extends into the far eastern Pacific along 82W and north of 04N. It is moving westward at 10 kt. Scattered showers and thunderstorms are along and near the wave axis from 05N to 08N between 80W and 83W. A tropical wave has an axis along 92W north of 04N to western Guatemala, moving westward at 10-15 kt. There is no significant convection associated with this wave at this time. A tropical wave has an axis along 132W from 08N to 14N, moving westward at 10-15 kt. Scattered moderate convection is noted from 10N to 12N between 131W to 132W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the Costa Rica coast near 10N86W to 13N96W to a 1009 mb low near 18N107W to 14N118W to 11N130W to 12N140W. Aside from the convection associated with the 1009 mb low and the tropical waves, scattered moderate to isolated strong convection is noted from 10N to 15N between 95W to 104W. Scattered moderate convection is noted from 09N to 15N between 110W to 128W and from 09N to 13N between 132W to 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on a low pressure system centered a couple hundred miles south- southeast of Manzanillo, Mexico. A weak trough extends from 30N118W to near 23N122W. No convection is occurring with this trough as it is surrounded by a very dry and stable environment. Moderate to locally fresh NNW winds are noted off the Baja California peninsula with seas to 5 ft in long-period S to SW swell. In the Gulf of California, light to gentle variable winds with seas less than 3 ft prevail. Isolated showers are noted in the Gulf of California. Light to gentle variable winds are also across the Nayarit offshores while moderate to fresh SE winds are observed off the coasts of Jalisco to Guerrero. Seas are up to 7 ft in long-period SW swell. Otherwise, increasing scattered showers and thunderstorms are observed over the offshore waters of Oaxaca to Jalisco. Winds will continue to be light to gentle off the Baja Peninsula today with locally moderate winds with seas to 4 ft. Gentle to moderate NW winds will return tonight and increase to moderate to fresh by Tue evening as the Special Features low pressure system approaches from the SE. In the Gulf of California, winds are expected to return to light tonight and continue through Thu. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Light to moderate southwest winds are south of the monsoon trough, while light and variable winds are north of the monsoon trough. Seas are 3 to 6 ft in the Central American offshore waters with 6 to 7 ft seas off of Ecuador and the Galapagos Islands. Scattered showers and thunderstorms are over the offshore waters of Nicaragua and Costa Rica along with Panama and the Gulf of Panama. Seas are 3 to 6 ft in the Central American offshore waters, except for higher seas of 6 to 7 ft over the waters between Ecuador and the Galapagos Islands due to a SW swell. These seas will increase slightly to 6-8 ft Mon night and Tue. Winds in Papagayo region will pulse moderate to locally fresh through Wed. Moderate to locally fresh SW winds are expected along the regions of Costa Rica, Panama, Colombia, Ecuador and Galapagos Islands Tue through Thu. Seas in this area will remain in the 6 to 7 ft range, except for 8 ft in the region west of Ecuador. REMAINDER OF THE AREA... Broad high pressure dominates the waters north of the monsoon trough, with the gradient between it and lower pressure to the south in the monsoon trough region allowing for moderate to locally fresh NNE winds and seas of 6 to 8 ft for the are north of about 12N and west of 120W. Gentle to moderate southerly winds remain south of the monsoon trough, with seas to 7 ft. An area of slightly stronger winds, in the fresh range, was noted in an overnight ASCAT pass to be confined between 118W-123W. Satellite imagery shows what appears to be a low forming along the monsoon trough near 13N119W. The low could be at the mid- levels as inferred from satellite imagery. Seas to 8 ft due to a SW swell continue south of the Equator and W of the Galapagos Islands. Otherwise, an area of low pressure is forecast to form in a few days well to the southwest of the southern tip of the Baja California peninsula. Environmental conditions appear conducive for gradual development of this system during the next few days, and a tropical depression is likely to form by midweek while it moves west-northwestward or northwestward at 5 to 10 mph, just offshore the coast of Mexico. This system has a medium chance of development in 48 hours and high chance in 5 days. In addition, another area of low pressure is forecast to form during the next couple of days well to the southwest of the southern tip of the Baja California peninsula. Some slow development of this system is possible thereafter while it meanders over the open eastern Pacific Ocean. There is a low chance of development in the next 48 hours and 5 days. Otherwise, moderate to fresh NNE winds are forecast for the northern waters W of Baja California by late Mon, continuing through Wed. $$ AReinhart