000 AXPZ20 KNHC 062153 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Low pressure of 1009 mb is located along the monsoon trough near 17N106W, or a couple of hundred miles south-southeast of Manzanillo, Mexico moving northwest near 10 kt. Satellite imagery shows somewhat better organized scattered moderate to isolated strong convection from 14N 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 kt, just offshore of the coast of Mexico. This system has a high chance of becoming a tropical cyclone during the next 48 hours. 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 83W and north of 03N into Costa Rica. 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 84W. A tropical wave has an axis along 93W north of 05N to the Gulf of Tehuantepec, moving westward at 10 kt. Scattered moderate convection is within 50 nm of the wave from 09N to 14N . A tropical wave has an axis along 133W from 09N to 14N, moving westward at 10 kt. Scattered moderate convection is noted from 11N to 13N between 132W to 133W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the coast of Nicaragua near 12N87W to 13N95W to a 1009 mb low near 17N106W to 15N118W to 11N129W to 11N140W. Aside from the convection associated with the 1009 mb low and the tropical waves, scattered moderate convection is noted from 05N to 13N between 79W and 100W. Scattered moderate convection is also noted from 09N to 15N between 110W and 128W, from 10N to 15N between 108W and 127W, and from 09N to 13N between 134W 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 30N120W to near 25N122W. No convection is occurring with this trough as it is surrounded by a very dry and stable environment. Latest scatterometer data depicts gentle to moderate NW winds off the Baja California peninsula with seas to 4 ft in long- period S to SW swell. In the Gulf of California, scatterometer data depicts moderate to locally fresh winds in the northern Gulf with light to gentle variable winds in the central and southern Gulf. Seas are less than 3 ft. Quiescent conditions prevail across the Gulf of California with no significant convection noted. Across southern Mexico, the latest scatterometer data showed fresh to strong winds are noted off the coasts of Jalisco to Guerrero in associated with the 1009 mb low in the Special Features section. Seas are up to 7 ft in this region. Otherwise, light to gentle variable winds are across the Nayarit offshores in addition to Oaxaca and Chiapas. Seas are 6 to 7 ft in long- period SW swell. Showers and thunderstorms in associated with the 1009 mb low continue across Jalisco to Guerrero. Winds will continue to be gentle to moderate off the Baja Peninsula tonight through Tue with seas to 5 ft. By Tue night, winds will become moderate to fresh as the low pressure system in the Special Features approaches the region from the SE. This system is expected to move across the offshores of the Baja Peninsula Wed through the end of the week with building seas. In the Gulf of California, winds are expected to return to light tonight and continue through Thu night. Light to gentle winds will continue across southern Mexico. By Fri, fresh to strong winds could develop across the Gulf of Tehuantepec and continue into the weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Latest scatterometer data depicts moderate to locally fresh winds continue across the Gulf of Papagayo. Meanwhile, gentle to moderate southwest winds are south of the monsoon trough with light and variable winds are north of the monsoon trough. Seas are 3 to 6 ft in the Central American offshore waters and 6 to 7 ft seas off of Ecuador and the Galapagos Islands. Satellite imagery shows strong thunderstorms are beginning to move off of the coast of Nicaragua to Panama into the adjacent offshore waters. Isolated thunderstorms are noted along the coast of Colombia. 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. Winds in Papagayo region will pulse moderate to locally fresh through Thu. Moderate to locally fresh SW winds are expected along the offshore waters of Costa Rica, Panama, Colombia, Ecuador and Galapagos Islands Tue through the end of the week. Seas in this area will remain in the 6 to 7 ft range, except near 8 ft seas 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 fresh NNE winds and seas 7 ft south of 15N and west of 115W. Gentle to moderate southerly winds remain south of the monsoon trough, with seas to 7 ft. An area of fresh winds was noted in a recent scatterometer pass near 119W. Satellite imagery shows what appears to be a low forming along the monsoon trough near 14N120W. The low is likely at the mid- levels and has not reached the surface. Seas to 8 ft due to a SW swell continue south of the Equator and W of the Galapagos Islands. A broad area of low pressure located several hundred miles southwest of the southern tip of the Baja California peninsula is producing disorganized showers and thunderstorms. Development of this system, if any, is likely to be slow over the next couple of days while it drifts northward. By late this week, environmental conditions are expected to become unfavorable for further development. This system has a low chance of development in the next 48 hours and 5 days. Otherwise, winds will begin to relax along the monsoon trough by Tue through the rest of the week. Moderate winds are forecast for the northern waters W of Baja California by late Mon, continuing through Thu. $$ AReinhart