000 AXPZ20 KNHC 151627 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1530 UTC. ...SPECIAL FEATURES... Hurricane Fernanda is centered near 17.0N 121.8W at 15/1500 UTC, moving west-northwest at 10 kt. Estimated minimum central pressure is 967 mb. Maximum sustained wind speed is 95 kt with gusts to 115 kt. Numerous moderate to scattered strong convection is noted within 100 nm in the center. Peak seas are near 30 ft with the 12 ft seas extending within 90 nm of the center. Fernanda will continue a west-northwestward to westward motion with an increase in forward speed during the next several days. Additional weakening is forecast during the next several days. Fernanda is expected to weaken to a tropical storm on Wednesday and become post-tropical 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 coasts of Mexico, Guatemala, and El Salvador. Environmental conditions appear conducive for development, and a tropical depression is expected to form within the next two 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 refer to the latest NHC Tropical Weather Outlook at wwww.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 97W from 06N northward into southern Mexico, moving W at 10 to 15 kt. A low pressure of 1007 mb is along the wave axis near 09.9N97.7W. Scattered moderate to isolated strong convection is observed from 07N to 16N between 94W and 103W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 10N86W to 10N110W and then from 12N124W to 10N133W. The ITCZ extends from 10N133W to 10N140W. Aside from the convection associated with the Tropical Wave mentioned above, scattered moderate to isolated strong is noted from 03N to 21N between 104W and 115W. Scattered moderate convection is noted from 04N to 13N between 118W and 136W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section on the Gale Warning in the Mexico offshores with EP90. Outside of EP90, a surface ridge dominates the offshore forecast waters of Baja California producing moderate to locally fresh NW to N winds. Seas are 4 to 5 ft N of Punta Eugenia, and 4 to 6 ft elsewhere. The fresh to strong N gap winds in the Gulf of Tehuantepec have now merged with EP90. In the Gulf of California, light to gentle west winds are observed per scatterometer data noted with seas of 1 to 3 ft, except seas of 3 to 4 ft near the entrance to the Gulf. Gentle to locally moderate 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 strong winds with seas ranging 8 to 10 ft is noted in the offshore waters of Guatemala and El Salvador as well as in parts of the offshore waters of Nicaragua and northern Costa Rica. These winds are related to the broad area of low pressure associated with EP90. Seas to 7 ft are also noted in the Nicaragua offshore waters due to EP90. Elsewhere, gentle to locally moderate SW to W winds prevail based on satellite derived wind data. Seas are generally 4 to 5 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, a broad area of low pressure associated with a tropical wave is producing widespread showers and thunderstorms off the southern coasts of Mexico, Guatemala, and El Salvador. Environmental conditions appear conducive for development, and a tropical depression is expected to form within the next two days or so, while the system moves west-northwestward, roughly parallel to the coast of southern and southwestern Mexico. This 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. ...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. Gentle to moderate winds and moderate seas prevail under the influence of the ridge. Seas range 4-7 ft. For the forecast, based on latest NHC forecast advisory, Fernanda will move to 17.3N 123.5W this evening, 17.5N 126.0W Wed morning, weaken to a tropical storm near 17.6N 128.6W Wed evening, 17.8N 131.4W Thu morning, become post-tropical and move to 18.0N 134.3W Thu evening, and weaken to a remnant low near 18.1N 137.4W Fri morning. Fernanda will change little in intensity as it moves to near 18.3N 143.8W by early Sat. $$ AKR