574 AXPZ20 KNHC 141617 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Aug 14 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... Major Hurricane Fernanda is centered near 15.8N 118.5W at 14/1500 UTC, moving west at 7 kt. Estimated minimum central pressure is 955 mb. Maximum sustained wind speed is 115 kt with gusts to 140 kt, which makes Fernanda a Category 4 hurricane. Satellite imagery continues to show a cyclone that is continuing to rapidly intensify. A well-defined eye is visible and is surrounded by thick eyewall. Numerous moderate to strong convection is within 100 nm of the center. Peak seas are currently around 38 ft with 12 ft seas extending 150 nm in the NE quadrant, 120 nm in the NW quadrant, and 90 nm in the southern semicircle. Fernanda will continue moving in a general west to west- northwest motion with some increase in forward speed over the next few days. Some additional strengthening could occur today. A weakening trend is expected to begin tonight or early Tuesday. Seas will continue to stay above 20 ft through Fri, with seas quickly 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. Tropical Storm Greg is now W of 140W and the Central Pacific Hurricane Center is issuing advisories on this system. For waters E of 140W, strong winds and seas to 11 ft are noted from 10N to 16N and W of 138W. These conditions will improve later today. For more information, please read the latest HIGH SEAS FORECAST issued by the National Weather Service Honolulu, Hawaii at website - https://weather.gov/hfo/HSFNP and the latest Greg CPHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. A tropical wave continues to produce a broad area of disorganized 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 few days, while the system moves west-northwestward, roughly parallel to the coast of southern and southwestern Mexico. This system has a medium chance of development in 48 hours and a high chance of development in 5 days. Please refer to the latest NHC Tropical Weather Outlook at wwww.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends off the Costa Rica coast near 08N84W to 08N106W, then from 12N122W to 12N134W. Scattered moderate to strong convection is noted from 04N to 17N between 82W and 111W. Scattered moderate convection is noted from 04N to 11N between 116W to 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge dominates the offshore forecast waters of Baja California. Moderate to fresh winds are noted in the Gulf of Tehuantepec with seas to 6 ft in mostly NW swell. Gentle to moderate NW to N winds are noted across the Baja California offshore waters along with seas of 4-6 ft. Inside the Gulf of California, light to gentle winds are noted with seas to 3 ft. Gentle to locally moderate winds are noted elsewhere off the southern Mexico offshore waters with 4-5 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. Fresh north gap winds in the Gulf of Tehuantepec will increase to fresh to strong speeds on Tue and will merge with a potential tropical system later in the period. Looking ahead, a tropical wave continues to produce a broad area of disorganized 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 few days, while the system moves west- northwestward, roughly parallel to the coast of southern and southwestern Mexico. This system has a medium chance of formation within 48 hours and high chance in 7 days. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh easterly winds are in the Gulf of Papagayo region extending westward to near 91W. Light to gentle westerly winds are elsewhere north of 05N, and mainly moderate south to southwest winds between the Equator and 05N. Gentle to moderate southerly winds are over the waters between Ecuador and the Galapagos Islands. Seas are generally 5-7 ft due to a long- period south to southwest swell, except 1-3 ft in the Gulf of Panama, and 3-5 ft offshore Colombia. For the forecast, the moderate to fresh easterly winds in the Gulf of Papagayo region will diminish early Tue. Elsewhere, gentle to moderate winds and moderate seas will continue through the week in most areas. Moderate south to southwest winds will become fresh over the waters between Ecuador and the Galapagos Islands starting Thu. Looking ahead, a tropical wave continues to produce a broad area of disorganized 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 few days, while the system moves west-northwestward, roughly parallel to the coast of southern and southwestern Mexico. ...REMAINDER OF THE AREA... Please refer to the section above for details on Hurricane Fernanda and on Tropical Storm Greg located W of the forecast area. Outside of the systems mentioned above, a weak pressure gradient remains west about 110W. A surface ridge remains in control of the weather conditions across the region. Gentle to moderate winds and moderate seas prevail under the influence of the ridge. Seas range 4-7 ft. For the forecast, latest NHC forecast advisory has Hurricane Fernanda continuing to be a Major Hurricane through Tue morning. Fernanda will move to 16.3N 119.6W this evening, 17.0N 121.4W Tue morning, 17.4N 123.6W Tue evening, 17.6N 126.2W Wed morning, weaken to a tropical storm near 17.8N 128.9W Wed evening, and 18.0N 131.8W Thu morning. Fernanda will become post- tropical as it moves near 18.3N 137.9W early Fri. $$ AReinhart