ZCZC MIATCPEP4 ALL TTAA00 KNHC DDHHMM BULLETIN Tropical Storm Hilary Advisory Number 19 NWS National Hurricane Center Miami FL EP092023 800 PM PDT Sun Aug 20 2023 ...CENTER OF HILARY MOVING NEAR THE COAST OF SOUTHERN CALIFORNIA... ...CATASTROPHIC AND LIFE-THREATENING FLOODING LIKELY OVER NORTHERN BAJA CALIFORNIA AND PORTIONS OF THE SOUTHWESTERN U.S. THROUGH MONDAY... SUMMARY OF 800 PM PDT...0300 UTC...INFORMATION ---------------------------------------------- LOCATION...33.9N 118.2W ABOUT 105 MI...170 KM NW OF SAN DIEGO CALIFORNIA MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...NNW OR 340 DEGREES AT 28 MPH...44 KM/H MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has discontinued the Tropical Storm Warning for the west coast of the Baja California peninsula and for the east coast of the Baja California peninsula south of San Felipe. The warning has also been discontinued south of Puerto Penasco along the coast of mainland Mexico. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * San Felipe to Puerto Penasco, Mexico * California/Mexico border to Point Mugu * Catalina Island A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning. 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 800 PM PDT (0300 UTC), the center of Tropical Storm Hilary was located near latitude 33.9 North, longitude 118.2 West. Hilary is moving toward the north-northwest near 28 mph (44 km/h), and this general motion is expected to continue into Monday. On the forecast track, the center of Hilary will move across portions of southern California through early Monday. Maximum sustained winds are near 45 mph (75 km/h) with higher gusts. Weakening is expected to continue, and Hilary is forecast to become a post-tropical cyclone by early Monday. Tropical-storm-force winds extend outward up to 230 miles (370 km), primarily to the east of the center. A sustained wind of 41 mph (66 km/h) and a gust of 54 mph (87 km/h) was recently reported at the Salton Sea in southern California. The estimated minimum central pressure based on surface observations is 998 mb (29.47 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 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. Intense heavy rainfall associated with Hilary is expected across the Southwestern United States through early Monday morning. Rainfall amounts of 3 to 6 inches, with isolated maximum amounts of 10 inches, are expected across portions of southern California and southern Nevada leading to dangerous to catastrophic flooding. Across portions of Oregon and Idaho, rainfall totals of 1 to 3 inches with local maxima to 5 inches are expected through Tuesday morning, resulting in localized, some significant, flash flooding. A list of rainfall observations compiled by the NOAA Weather Prediction Center for this storm can be found at: www.wpc.ncep.noaa.gov/discussions/nfdscc4.html WIND: Tropical storm conditions will continue for the next few hours within the Tropical Storm Warning area along the northern Gulf of California. Tropical storm conditions will continue into tonight in the warning area in southern California. 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: Coastal flooding is possible along the northern coast of the Gulf of California through early Monday. TORNADOES: A brief tornado or two will be possible this evening across southeast California, northwest Arizona, southern Nevada and far southwest Utah. SURF: Large swells generated by Hilary will affect portions of the Baja California Peninsula and southern California through early Monday. 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 1100 PM PDT. Next complete advisory at 200 AM PDT. $$ Forecaster Reinhart NNNN