ZCZC MIATCPEP4 ALL TTAA00 KNHC DDHHMM BULLETIN Hurricane Hilary Advisory Number 15 NWS National Hurricane Center Miami FL EP092023 900 PM MDT Sat Aug 19 2023 ...HEAVY RAINS CONTINUE TO SPREAD NORTHWARD OVER THE BAJA PENINSULA AND THE SOUTHWESTERN UNITED STATES... ...CATASTROPHIC AND LIFE-THREATENING FLOODING LIKELY... SUMMARY OF 900 PM MDT...0300 UTC...INFORMATION ---------------------------------------------- LOCATION...25.3N 114.6W ABOUT 175 MI...280 KM S OF PUNTA EUGENIA MEXICO ABOUT 535 MI...855 KM SSE OF SAN DIEGO CALIFORNIA MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/H PRESENT MOVEMENT...NNW OR 345 DEGREES AT 18 MPH...30 KM/H MINIMUM CENTRAL PRESSURE...968 MB...28.59 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has discontinued the Tropical Storm Warning on the east coast of the Baja California Peninsula south of Los Barilles, and on the west coast of the Baja California Peninsula south of Todos Santos, SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Baja California peninsula from Punta Abreojos to Cabo San Quintin A Hurricane Watch is in effect for... * Baja California peninsula north of Cabo San Quintin to Ensenada A Tropical Storm Warning is in effect for... * Baja California peninsula from Punta Abreojos to Todos Santos * Baja California peninsula east coast from Los Barilles northward * Baja California peninsula north of Cabo San Quintin to the California/Mexico border * Mainland Mexico north of Guaymas * California/Mexico border to Point Mugu * Catalina Island A Tropical Storm Watch is in effect for... * Mainland Mexico from Huatabampito to Guaymas A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A Hurricane Watch means that hurricane conditions are possible within the watch area, in this case within the next 12 to 24 hours. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Interests elsewhere in the southwestern U.S. should monitor the progress of Hilary. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 900 PM MDT (0300 UTC), the center of Hurricane Hilary was located near latitude 25.3 North, longitude 114.6 West. Hilary is moving toward the north-northwest near 18 mph (30 km/h). The hurricane is expected to accelerate as it moves north-northwestward to northward during the next day or two. On the forecast track, the center of Hilary will move close to the west-central coast of the Baja California Peninsula tonight and Sunday morning then move across southern California Sunday afternoon. Maximum sustained winds are near 90 mph (150 km/h) with higher gusts. Continued weakening is expected, but Hilary is likely to still be a hurricane when it approaches the west coast of the Baja California Peninsula later tonight. Hilary is expected to weaken to a tropical storm before it reaches southern California. Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 265 miles (425 km). A sustained wind of 58 mph (93 km/h) and a gust of 69 mph (111 km/h) were reported at Loreto, Mexico, within the past couple of hours. The estimated minimum central pressure is 968 mb (28.59 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Hilary can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP4 and WMO header WTPZ44 KNHC and on the web at hurricanes.gov/text/MIATCDEP4.shtml. RAINFALL: Hilary is expected to produce storm total rainfall amounts of 3 to 6 inches, with isolated maximum amounts up to 10 inches, across portions of the northern Baja California Peninsula through Sunday night. Flash and urban flooding, locally catastrophic, is expected, especially in the northern portions of the peninsula. Heavy rainfall in association with Hilary is expected across the Southwestern United States, peaking during the next day or so. Rainfall amounts of 3 to 6 inches, with isolated amounts of 10 inches, are expected across portions of southern California and southern Nevada. Dangerous to catastrophic flooding is expected. Elsewhere across portions of the Western United States, rainfall totals of 1 to 3 inches are expected, resulting in localized significant flash flooding. WIND: Hurricane conditions are expected within the hurricane warning area tonight and early Sunday and are possible within the hurricane watch area on Sunday. Tropical storm conditions are occurring within the southern portion of the tropical storm warning area and will spread northward tonight and Sunday. Tropical storm conditions are possible within the tropical storm watch area through early Sunday. Tropical storm conditions are expected to begin in southern California on Sunday. Winds could be particularly strong and gusty in and near areas of elevated terrain. Higher gusts are expected well inland and will persist even after the system becomes post-tropical. STORM SURGE: A dangerous storm surge is likely to 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. Coastal flooding is possible along the northern coast of the Gulf of California Sunday through early Monday. TORNADOES: A tornado or two may occur Sunday from mid-morning through the evening over parts of the lower Colorado River Valley, Mojave Desert, and Imperial Valley regions. SURF: Large swells generated by Hilary will affect portions of the Baja California Peninsula and southern California over the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 1200 AM MDT. Next complete advisory at 300 AM MDT. $$ Forecaster Brown NNNN