847 AXPZ20 KNHC 141552 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. 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 gnetle 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 are forecast to pulse in the Tehuantepec region today, and may increase to fresh to strong speeds beginning on Tue through the end of the forecast period as a tropical depression is expected to form from an area of disorganized showers and thunderstorms over the eastern Pacific associated with a tropical wave. The tropical system is expected to move generally west-northwestward, roughly parallel to the coast of southern and southwestern Mexico though the week. ...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 3-5 ft due to a long- period south to southwest swell, except 1-3 ft in the Gulf of Panama, and 3-6 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, except the moderate south to southwest winds over the waters between Ecuador and the Galapagos Islands will increase to fresh speeds starting Thu. Looking ahead, a tropical wave along 95W is producing a large area of disorganized showers and thunderstorms over the far eastern portion of the east Pacific. Environmental conditions appear conducive for development, and a tropical depression is expected to form in the next few days, while the system moves west-northwestward, roughly parallel to the coast of southern and southwestern Mexico. Expect increasing winds, seas, and unsettled weather during this time mainly over the offshore waters from El Salvador north to Guatemala. ...REMAINDER OF THE AREA... Please refer to the section above for details on Hurricane Fernanda and on newly upgraded Tropical Storm Greg located in the extreme western part of the 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. For the forecast, latest NHC forecast advisory has Hurricane Fernanda continuing to rapidly intensify over the next day or so. It is forecast to become a Category today. It is forecast to reach near 15.9N 118.8W by early this afternoon with a maximum sustained wind speed of 125 kt with gusts to 150 kt, then begin to gradually weaken as it reaches near 16.5N 120.5W by late tonight with a maximum sustained wind speed of 110 kt with gusts to 135 kt, to near 17.0N 122.5 with a maximum sustained wind speed of 100 kt with gusts to 120 kt by early Tue afternoon and to near 17.3N 124.9W by late Tue night with a maximum sustained wind speed of 85 kt with gusts to 105 kt by late Tue night. Fernanda is forecast to weaken to a tropical storm near 17.5N 130.3W by late Wed night and weaken further to a post- tropical remnant low west of the area by late Fri night near 18N.5N 142.7W. $$ AKR