000 AXPZ20 KNHC 152145 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Aug 15 2023 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... Hurricane Fernanda is centered near 17.3N 122.8W at 15/2100 UTC, moving west at 10 kt. Estimated minimum central pressure is 971 mb. Maximum sustained wind speed is 90 kt with gusts to 110 kt. Numerous moderate to scattered strong convection is noted within 90 nm in the center. Peak seas are near 30 ft with the 12 ft seas extending 120 nm in the NE quadrant, 105 nm in the NW quadrant, and 90 nm in the southern semicircle. Fernanda will continue to move in a general westward motion with a slight increase in forward speed during the next several days. Additional weakening is forecast during the next several days. Fernanda is expected to become a tropical storm on Wednesday and weaken to a post- tropical cyclone on Thursday. Seas will continue to stay above 20 ft through Wed night into Thu, with seas subsiding by the end of the week as the system approaches 140W. 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 Fernanda NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gale Warning (EP90): A broad area of low pressure associated with a tropical wave is producing widespread showers and thunderstorms off the southern coast of Mexico. Environmental conditions appear conducive for development, and a tropical depression is expected to form within the next couple of days or so, while the system moves west-northwestward, roughly parallel to the coast of southern and southwestern Mexico. Additional information on this system, including gale warnings, can be found in High Seas Forecasts issued by the National Weather Service. This system has a high chance of tropical cyclone formation within 48 hours. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and refer to the latest NHC Tropical Weather Outlook at wwww.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 99W from 06N northward into southern Mexico, moving W at 5 to 10 kt. A low pressure of 1007 mb is along the wave axis near 10N99W. Scattered moderate to isolated strong convection is noted west of the low from 06N to 14N between 98W and 106W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 10N86W to 10N110W and then from 12N124W to 09N133W. The ITCZ extends from 09N133W to beyond 11N140W. Aside from the convection associated with the Tropical Wave mentioned above, scattered moderate convection is noted from 07N to 18N between 108W and 125W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section on the Gale Warning in the Mexico offshores due to EP90. Outside of EP90, a surface ridge dominates the offshore forecast waters of Baja California. This is causing moderate to locally fresh NW to N winds off Baja California Norte with gentle to locally moderate winds elsewhere in the Baja California offshore waters. Seas are 4 to 6 ft. In the Gulf of California, light to gentle variable winds are noted with seas of 1 to 2 ft, except seas of 3 to 4 ft near the entrance to the Gulf. Light to gentle winds are noted elsewhere off the southern Mexico offshore waters with 4-6 ft seas in SW swell. For the forecast, moderate to fresh NW winds are expected offshore the coast of Baja California from Punta Eugenia to Cabo San Lazaro mainly at night through the next few days. Please see the Special Features section for more information on EP90. Looking ahead, an area of low pressure could form south of the Gulf of Tehuantepec over the weekend. Some gradual development of this system is possible thereafter while it moves generally westward.This system has a low chance of development over the next 48 hours and 7 days. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... An area of fresh to locally strong winds with seas to 8 ft is noted in the offshore waters of Guatemala and El Salvador. These conditions are related to the broad area of low pressure associated with EP90. Elsewhere, moderate winds are noted in the Gulf of Papagayo with gentle to locally moderate SW to W winds elsewhere across the Central and South American offshore waters. Seas are generally 4 to 6 ft due to long- period SW swell, except 1 to 3 ft in the Gulf of Panama, and 3 to 4 ft offshore Colombia. For the forecast, the broad area of low pressure near southern Mexico will bring strong winds and rough seas to Guatemala and El Salvador offshore waters through Wed morning. Meanwhile, winds will pulse fresh to locally strong in the Gulf of Papagayo at night through the rest of the week. Winds will increase to moderate across the Galapagos Islands and Ecuador offshore waters by Wed night and will persist the rest of the week. Expect moderate seas within S to SW swell in this area. ...REMAINDER OF THE AREA... Please refer to the Special Features section above for details on Hurricane Fernanda. A ridge dominates roughly the waters N of 20N and W of 110W. Light to gentle winds are noted under the influence of the ridge, N of 21N and W of 119W. Seas range 4-6 ft in this area within NW swell. Gentle to moderate winds are noted N of the ITCZ/monsoon trough to 21N and W of Fernanda with seas 4-7 ft. Gentle to moderate S to SW winds are noted S of the ITCZ/monsoon trough with seas 5-8 ft in mostly S swell. For the forecast, based on latest NHC forecast advisory, Fernanda will move to 17.4N 124.6W Wed morning, 17.6N 127.2W Wed afternoon, weaken to a tropical storm near 17.7N 129.9W Thu morning, become post-tropical and move to 17.9N 132.8W Thu afternoon, weaken to a remnant low near 18.2N 135.8W Fri morning, and 18.4N 138.8W Fri afternoon. Fernanda will change little in intensity as it moves to near 18.4N 144.9W by Sat afternoon. $$ AReinhart