000 AXPZ20 KNHC 182159 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 1605 UTC Fri Aug 18 2023 Corrected Special Features section 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 1545 UTC. ...SPECIAL FEATURES...Corrected Hilary is an impressive major and powerful Category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. It is centered near 17.9N 111.4W at 18/1500 UTC, moving northwest at 9 kt. Estimated minimum central pressure is 939 mb. Maximum sustained wind speed is 125 kt with gusts to 150 kt. Satellite imagery clearly shows the eye of Hilary, about 15-20 nm in diameter. Numerous strong convection is tightly coiled around the eye, within 60 nm in the S semicircle. Numerous moderate to strong convection is elsewhere within 90 nm of the center from 16N to 19N between 109W-112W. A wide outer rain band consists of numerous moderate to strong convection within 45 nm of a line from 16N108W to 14N111W to 15N114W, and continues within 30 nm of a line from 15N114W to 19N114W. Scattered moderate to isolated strong convection is within 60 nm of a line from 09N117W to 10N112W to 13N109W. The 12 ft seas radii continues to expand. It extends outward within 210 nm W semicircle, 360 nm NE quadrant and 330 nm SE quadrant, with maximum seas to 42 ft. Meanwhile, the elsewhere 8 to 12 ft seas cover the area roughly from 07N to 23N between 101W-116W, including the waters near Cabo Corrientes, between Las Marias Islands and Los Cabos as well as the entrance of the Gulf of California, and the southern part of the Gulf to about 24N. On the forecast track, a turn toward the northwest and north- northwest is expected today and tonight, followed by a faster motion toward the north Sat night and Sun. The center of Hilary will move close to the west coast of the Baja California peninsula over the weekend and reach southern California by Sun night. Fluctuations in intensity are likely over the next day or so. Weakening is expected to begin by Sat, but Hilary will still be a hurricane when it approaches the west coast of the Baja California peninsula Sat night and Sun. Hilary is expected to weaken to a tropical storm by Sun afternoon before it reaches southern California. Hilary is forecast to produce rainfall amounts of 3 to 6 inches, with isolated maximum amounts up to 10 inches, across portions of southern California and southern Nevada. Rare and dangerous flooding will be possible. Elsewhere across portions of the Western United States, rainfall totals of 1 to 3 inches are expected. A storm surge could produce coastal flooding along the western Baja California peninsula of Mexico near where the center passes the coast in areas of onshore winds, or east of the center if Hilary makes landfall. The surge will be accompanied by large and destructive waves. 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. Interests elsewhere on the Baja California peninsula and along the coast of northwestern mainland Mexico and the southwestern United States coastline should closely monitor the progress of Hilary. 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 Hilary NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 94W from 04N northward to across the Gulf of Tehunatepec. It is moving westward around 10 kt. Numerous moderate to isolated strong convection is seen from 10N to 14N between the wave and 89W. Scattered moderate to isolated strong convection is within 30 nm of the wave from 04N to 06N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from along the coast of northwest Colombia to central Costa Rica, to 10N84W to 07N95W to 12N102W. It resumes south of Hurricane Hilary at 11N120W and continues to 09N131W to beyond 06N140W. Scattered moderate to isolated strong convection is within 30 nm of the trough between 123W-126W. Scattered moderate convection is within 30 nm of the trough between 120W-127W, and within 30 nm south of the trough between 137W-139W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information on powerful Hurricane Hilary. Outside of Hurricane Hilary, a ridge dominates the offshore forecast waters of Baja California N of Cabo San Lazaro while the outer cyclonic circulation of Hilary is approaching the waters between Las Maria Islands and Los Cabos. The associated pressure gradient is allowing for gentle to moderate NW to N winds N of Cabo San Lazaro. Seas are 4-6 ft within these winds. In the Gulf of California, gentle to moderate southerly winds prevail, except in the southern part of the Gulf where moderate to fresh winds are present. Wave heights continue to increase near the entrance to the Gulf of California as seas generated by Major Hurricane Hilary continues to spread in all directions. Moderate to fresh north winds and seas to about 7 ft are in the Tehuantepec region. For the forecast, Hilary is forecast to move near 19.2N 112.5W this evening with maximum sustained winds 130 kt gusts 160 kt, then begin to gradually weaken as it turns to the north- northwest reaching near 21.3N 113.6W Sat morning, to near 23.7N 114.4W Sat evening with maximum sustained winds 100 kt gusts 120 kt, to near 26.8N 115.2W Sun morning with maximum sustained winds 85 kt gusts 105 kt, to near 30.4N 116.4W Sun evening with maximum sustained winds 65 kt gusts 80 kt and move inland and weaken to a tropical storm near 35.2N 117.4W Mon morning and dissipate early Tue. Very rough seas and tropical storm conditions are expected in the Gulf of California this upcoming weekend. Fresh to strong N winds are forecast in the Gulf of Tehuantepec at night through Sun night. Looking ahead, a broad area of low pressure could form offshore of the coast of southern Mexico early next week. Some gradual development of this system is possible thereafter while it moves slowly toward the west- northwest or northwest, generally parallel to the coast of southern and southwestern Mexico. Looking ahead, a broad area of low pressure could form offshore of the coast of southern Mexico early next week. Some gradual development of this system is possible thereafter while it moves slowly toward the west-northwest or northwest, generally parallel to the coast of southern and southwestern Mexico. 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... Moderate to fresh northeast to east winds are in the Papagayo region and downwind to about 89W. Seas are 5-7 ft with these winds. Gentle to moderate winds and seas in the 4-6 ft range prevail elsewhere across the Central and South America forecast waters, with the exception of 1-3 ft seas in the Gulf of Panama, and 3-4 ft just offshore Colombia. For the forecast, moderate to fresh winds will prevail in the Papagayo region through Sat night, then mainly gentle to moderate winds and moderate seas in SW swell are forecast. Fresh SW to W winds and building seas to 8 or 9 ft are expected across the offshore waters from northern Costa Rica to western Panama Sun night through Tue night. This could be associated with a developing low pressure along the monsoon trough. Elsewhere across the offshore forecast waters of Central and South America, gentle to moderate winds and moderate seas are expected through the early next week. ...REMAINDER OF THE AREA... The remnant low of former tropical cyclone Fernanda is analyzed near 16N137W with a pressure of 1006 mb. Fresh to strong winds are still noted within 180 nm N and 60 nm S semicircles of center with seas of 8-12 ft. This system is forecast to cross 140W late tonight, and associated conditions will shift west of 140W by early Fri afternoon. A ridge dominates most of the waters N of 20N and W of 120W. The pressure gradient between the ridge and the remnant low pressure supports an area of moderate to fresh winds from 19N to 23N between 130W and 140W. Light to gentle winds are noted elsewhere under the influence of the ridge. Moderate to fresh winds are south of the monsoon trough roughly between 103W-122W due to the large circulation of Hilary. Elsewhere, seas are generally 4-7 ft in mixed swell. $$ Aguirre