000 AXPZ20 KNHC 161553 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Sep 16 2022 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 1200UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Tropical Storm Lester is centered near 13.7N 96.5W at 16/1500 UTC moving NW at 7 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Numerous moderate to strong convection is within 150 nm W semicircle. Scattered moderate to isolated strong convection is elsewhere from 12N to 16N between 98w and 103W. similar convective activity is also noted N of 14.5N between 94W and 96.5W, including the Gulf of Tehuantepec. On the forecast track, the center of the cyclone is expected to move near or over the coast of southwestern Mexico Saturday or Saturday night, and dissipate over southwestern Mexico on Sunday. Gradual strengthening is forecast during the next day or so. Rapid weakening is expected after the center crosses the coast of Mexico. Lester is expected to produce rainfall totals of 3 to 6 inches with local maximum totals of 10 inches across coastal portions of the Mexican States of western Oaxaca, Guerrero, Michoacan, Colima, and Jalisco through Monday. These rains may produce flash and urban flooding, along with possible mudslides in areas of higher coastal terrain. Swells generated by Lester are affecting portions of the coast of southern Mexico and this will continue into the weekend. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest T.D. Thirteen-E NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Southwest of Southwestern Mexico: An area of low pressure located a few hundred miles south- southwest of Manzanillo, Mexico, continues to produce disorganized showers and thunderstorms. Environmental conditions are forecast to become more conducive for development, and a tropical depression is likely to form within the next couple of days. This disturbance is forecast to meander off the southwestern coast of Mexico through the end of this week, and then begin to move northwestward early next week. A cluster of moderate to strong convection is within 120 nm SW quadrant. Scattered moderate to isolated strong convection is elsewhere from 13.5N to 16N between 104W and 107W. Another cluster of moderate to isolated strong convection is from 13N to 17N between 109W and 112W. A broad area of fresh to strong SW-W winds is S of the monsoon trough in the vicinity of the low center, covering the waters from 08N to 14N between 100W and 110W. Seas of 8-11 ft in long period S to SW swell are occurring across this area. The latest Tropical Weather Outlook gives this system a high chance of tropical cyclone formation within the next 48 hours. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details on both areas. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N85W to T.S. Lester located near 13.5N96.5W, then resumes from near 14N100W to low pres situated near 14.5N107W to 12N120W to another low pres located near 12N135W to 08N140W. Aside for the convection associated with Lester and the low pressure, scattered moderate to isolated strong convection is noted N of 04N E of 80W including the Gulf of Panama. Scattered moderate convection is from 06N to 11N between 80W and 91W, and from 12N to 14N between 130W and 139W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the Special Features section for details on T.S. Lester and a low pressure area located a few hundred miles south- southwest of Manzanillo, Mexico. Moderate to locally fresh NW to N winds prevail across the offshore waters of Baja California and extend southward to near 22N. Seas across this area are 5-7 ft. Light to gentle winds and seas of 1-3 ft prevail in the Gulf of California. Marine conditions S of Cabo Corrientes are related to the above mentioned low pressure area with a high chance of tropical cyclone formation. Cross equatorial S swell dominates these waters with seas of 4-6 ft. For the forecast, Lester will move to 14.4N 97.6W this evening, 15.7N 99.1W Sat morning, 17.2N 100.8W Sat evening, move inland and weaken to a tropical depression near 18.7N 102.7W Sun morning, and dissipate Sun evening. High pressure will persist NW of Baja during the next few days and maintain moderate to fresh winds. Gentle to occasionally moderate mainly southerly winds and 1-3 ft seas are expected in the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh W-SW winds prevail south of the monsoon trough, while light and variable winds prevail north of the trough from the Gulf of Papagayo region to Guatemala coastal waters. Seas are 5-7 ft in SW swell across the offshore waters, with the exception of 6-8 ft between Ecuador and the Galapagos Islands, as well as offshore Guatemala. A moist and unstable environment interacting with the monsoon trough persists across the area, mainly N of 05N, resulting in active showers and thunderstorms. For the forecast, mainly gentle to moderate winds will persist across the offshore forecast waters, with seas of 6-9 ft in SW swell. Winds could increase to moderate to fresh between northern Costa Rica and Guatemala toward the upcoming weekend as a broad area of low pressure develops along the monsoon trough. A very moist and unstable atmospheric environment will help maintain active weather across most of the offshore waters over the next few days. REMAINDER OF THE AREA... Refer to the Special Features section for details on T.S. Lester and a low pressure area located a few hundred miles south- southwest of Manzanillo, Mexico. High pressure dominates the waters north of the monsoon trough and west of about 120W, centered on a 1023 mb high near 29N132W. The related modest pressure gradient is allowing for mostly light to gentle winds over the NW corner of the forecast area. Gentle to moderate winds prevail elsewhere north of the monsoon trough. Seas are 5-7 ft, in long period southerly swell. NE winds around 20 kt and seas 7 to 8 ft are seen within 180 nm across the N semicircle of 1012 mb low pressure near 12.5N134W. Moderate to locally fresh southerly winds are south of the monsoon trough along with 5-8 ft seas, outside of T.S. Lester and a low pressure area located a few hundred miles south- southwest of Manzanillo, Mexico. For the forecast, high pressure will build across the northern forecast waters over the next few days, as a dry and benign cold front sinks across the NW waters. This pattern will support gentle to moderate winds and seas of 4-7 ft. Winds and seas will increase some between the ridge and a transient low pressure located along the monsoon trough between 130W and 140W. Additional pulses of cross- equatorial SW swell will continue to propagate across the forecast waters east of 130W. Weather conditions will deteriorate across the offshore waters from Oaxaca to Michoacan due to the approach of Lester. $$ GR