000 AXPZ20 KNHC 161552 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Aug 16 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... Newly upgraded Tropical Storm Hilary is centered near 12.4N 102.6W at 16/1500 UTC, moving west-northwest at 12 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Numerous strong convection covers a widespread area in the Mexico offshore waters and the high seas from 08N to 18N between 99W and 108W. Peak seas are currently around 17 ft with the 12 ft seas extending within 240 nm in the NE quadrant, 210 nm in the SE quadrant, 180 nm NW quadrant and 90 nm in the SW quadrant. Hilary will continue moving in a west- northwest motion with a gradual turn to the northwest in a day or so. Steady to rapid strengthening is forecast for the next few days. Hilary is expected to become a hurricane on Thursday. Large swells generated by Hilary will affect portions of the coast of southwestern Mexico and the Baja California peninsula over the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. Seas are expected to become high or very high by Thu and phenomenal Fri. 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. Newly downgraded Tropical Storm Fernanda is centered near 17.1N 126.8W at 16/1500 UTC, moving west at 13 kt. Estimated minimum central pressure is 994 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Some showers are around the system but no significant convection is noted at this time. Seas are around 25 ft with the 12 ft seas extending 120 nm in the NE quadrant and 90 nm in the NW quadrant and southern semicircle. Fernanda will continue moving west over the next few days. Continued rapid weakening is forecast during the next 48 hours, and Fernanda is likely to become a post-tropical remnant low within a couple of days. 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. ...TROPICAL WAVES... A tropical wave is along 88W from 10N northward to the coast of El Salvador, moving W at 5 to 10 kt. Isolated showers and thunderstorms are noted within 50 nm of the axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 07N81W to 12101W to 13N120W. The ITCZ extends from 07N133W to beyond 08N140W. Scattered moderate to isolated strong convection is noted from 01N to 08N between 79W and 90W. Scattered moderate convection is noted from 06N to 14N between 109W and 129W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features for information on Tropical Storm Hilary. 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. Higher winds are noted near the Sonora/Sinaloa border due to the presence of convective activity. Light to gentle winds are 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 west-northwestward. This system has a low chance of tropical cyclone development over the next 48 hours, and 7 days. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally strong winds are seen in the Papagayo region, and downwind to near 88W. Recent scatterometer data indicate moderate to fresh N winds across the Gulf of Panama to about 08N. Similar wind speeds are also noted near the Colombia/Ecuador border. Light to gentle winds are elsewhere across the Central America 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 just offshore Colombia. For the forecast, fresh to locally strong winds are expected in the Papagayo region trough Thu night. The broad area of low pressure near southern Mexico will continue to move westward and away from the Guatemala and El Salvador offshore waters tonight into Wed. Winds will increase to moderate between Ecuador and the the Galapagos Islands 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 115W. The pressure gradient between the ridge and tropical cyclone Fernanda supports an area of moderate to fresh winds mainly from 16N to 22N between 118W and 134W based on satellite derived wind data. Light to gentle winds are noted elsewhere under the influence of the ridge. Seas range 4-6 ft in this area within NW swell. For the forecast, based on latest NHC forecast advisory, Fernanda will weaken to a tropical storm near 17.2N 127.5W this afternoon, move to 17.1N 130.2W Thu morning, become post-tropical and move to 17.2N 132.9W Thu afternoon, weaken to a remnant low near 17.3N 135.7W Fri morning, 17.5N 138.7W Fri afternoon, and will be W of area near 17.7N 141.6W Sat morning. Fernanda will change little in intensity as it moves to near 17.7N 147.6W early Sun. $$ AKR