Eastern Pacific Tropical Weather Discussion
369 AXPZ20 KNHC 200949 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Sep 20 2026 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 0600 UTC surface analysis and satellite imagery through 0950 UTC. ...SPECIAL FEATURES... Former Invest EP98 became Tropical Storm Odalys, which is centered near 11.4N 124.5W at 20/0900 UTC, moving northwest at 7 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas are 8 to 10 ft at the moment. Numerous moderate to strong convection extends from 06N to 13N between 122W and 132W with scattered moderate isolated strong convection elsewhere from 02N to 17N between 117W and 139W. Odalys is moving toward the northwest near 7 kt, and this general motion is expected to persist over the next couple of days. Gradual strengthening is forecast during the next 48 hours, and Odalys is forecast to become a hurricane by Monday. 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 Odalys NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Storm warning (EP99): Showers and thunderstorms associated with a broad area of low pressure located about 400 miles south- southwest of Manzanillo, Mexico have become better organized over the past several hours. However, satellite-derived winds do not yet show a well-defined circulation. Environmental conditions remain conducive for development, and a tropical depression is likely to form within the next day or so as the system moves generally northward off the coast of southwestern Mexico. There is a high chance of tropical cyclone formation in the next 48 hours. Regardless of development, this system is forecast to bring gale to storm force winds and rough to very rough seas over the offshore waters from Guerrero to Jalisco through Thu night. In anticipation of tropical cyclone development, a storm warning has been issued for this area. Please refer to the latest NHC Tropical Weather Outlook at website: www.hurricanes.gov for more details on these Invests. ...TROPICAL WAVES... A tropical wave moving across the western Caribbean Sea with axis near 84W extends southward across Costa Rica and its offshore waters. It is moving westward near 5-10 kt. Scattered moderate to isolated strong convection is from 01N to 13N E of 96W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 13N106W to 11N124W to 14N140W. Numerous moderate to strong convection associated with Invest EP99 extends from 12N to 15N between 102W and 107W with scattered moderate isolated strong convection elsewhere from 06N to 18N between 96W and 115W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see SPECIAL FEATURES above for more on a storm warning associated with EP99, which has a high chance for TC development in the next 48 hours. Moderate to locally fresh NW winds and moderate seas prevail across the Baja California offshores N of Cabo San Lazaro. Otherwise, except for the Guerrero and Michoacan outer offshores where winds and seas are have deteriorated due to Invest EP99, moderate or weaker winds are elsewhere along with moderate seas. Slight seas prevail along the Gulf of California. For the forecast, aside from conditions associated with Invest EP99, moderate to locally fresh NW winds will prevail across the offshore Baja California waters through early Fri morning when conditions in Baja Calaifornia Sur offshores will start to deteriorate due to the proximity of Invest EP99. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate or weaker winds are across the region along with moderate seas. For the forecast, gentle to moderate winds and moderate seas will prevail through Thu night across the offshores. ...REMAINDER OF THE AREA... Please see SPECIAL FEATURES above for details on newly formed Tropical Storm Odalys. Tropical Storm Odalys is near 11.4N 124.5W at 2 AM PDT, and is moving northwest at 7 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1005 mb. The pressure gradient between Odalys and the monsoon as well as a 1024 mb high centered N of the area near 33N136W is supporting moderate to fresh, locally strong, winds N of the monsoon trough to near 28N and W of 130W. Moderate to rough seas cover these waters. Elsewhere, moderate winds and moderate seas are N of the monsoon trough. Fresh to strong southerly winds are feeding into EP99, where rough seas prevail. Elsewhere S of the monsoon trough, moderate or weaker winds and moderate seas, prevail. For the forecast, Odalys will move to 12.0N 125.6W this afternoon, 13.3N 127.1W Mon morning, strengthen to a hurricane near 14.4N 128.3W Mon afternoon, 15.0N 128.9W Tue morning, 15.2N 128.7W Tue afternoon, and 15.3N 128.0W Wed morning. Odalys will change little in intensity as it moves near 15.6N 126.5W early Thu. Otherwise, outside of conditions with EP99, gentle to moderate winds and moderate seas will prevail.