On August 19th, 2023, a historic event unfolded as Southern California faced its first-ever tropical storm warning. The warning, which spanned from Los Angeles to the U.S.-Mexico border and included the coastal region of San Diego, came as Hurricane Hilary approached the area. This tropical storm warning was accompanied by a flood warning for San Diego County.
The significance of this warning was not lost on many, as it had been nearly 84 years since a tropical storm had made landfall in California. The last time such an event occurred was in September of 1939.[0] While Hilary was not expected to make landfall as a hurricane, it had the potential to reach Southern California as a tropical storm, bringing with it strong winds, heavy rain, and the threat of flooding.
In preparation for the storm, Governor Gavin Newsom declared a state of emergency for much of Southern California.[1] This declaration aimed to mobilize and coordinate resources to support response and recovery efforts.[0] The forecast predicted rainfall totals of 2 to 4 inches in San Diego and Los Angeles, with higher amounts of 6 to 8 inches or more in higher elevations and desert areas to the east.[2]
As the storm approached, flood watches were issued for southwestern Arizona and southeastern California.[3] The National Weather Service warned of the potential for significant and localized catastrophic flooding in these areas, with rainfall amounts of 1 to 5 inches and isolated higher amounts.[3]
To mitigate the potential damage from flooding, residents were encouraged to pick up sandbags from various locations across the affected areas.[4] Fire stations in cities like Pasadena and Palm Springs provided sand and empty bags for residents to fill and protect their properties.[4]
The National Hurricane Center closely monitored Hurricane Hilary’s path as it weakened from a Category 2 hurricane to a tropical storm. While the storm was expected to weaken further as it moved north-northwest towards Southern California, it still posed a threat of power outages, downed trees, closed roads, flooding, and wind damage.
The potential for “life-threatening and potentially catastrophic flooding” prompted the issuance of tropical storm warnings for parts of Southern California. The National Weather Service’s Weather Prediction Center even issued a “high” risk outlook for excessive rains and flash flooding in the Southern California desert region.[2] This level of risk was exceptionally rare and could result in three to six inches of rain, with isolated higher amounts of 10 inches in mountainous areas.
As the storm neared Southern California, evacuation orders and warnings were issued for several communities. The San Bernardino County Sheriff’s Department ordered evacuations for Oak Glen, Forest Falls, Mountain Home Village, Angelus Oaks, and Northeast Yucaipa.[5] In Orange County, warnings were issued for residents near the Bond Fire burn scar.[6] The Los Angeles County Sheriff’s Department also advised visitors and residents on Catalina Island to leave ahead of the storm.[6]
With the storm moving faster than expected at 18 mph, it was crucial for residents and officials to be prepared.[7] More than 7,500 personnel were deployed to help protect Californians from the storm’s impact, according to Governor Newsom’s office.[1] The storm’s weakened state and faster speed did not diminish the need for caution and preparedness.
As Hurricane Hilary approached Southern California, it carried the potential for significant rainfall and flash flooding. In desert areas, up to 5 to 10 inches of rain were expected, posing a threat of flash floods.[8] The storm’s impact extended beyond California, with Arizona also preparing for possible effects.
Overall, the first-ever tropical storm warning in Southern California marked a historic event. It served as a reminder of the region’s vulnerability to extreme weather events and the importance of preparedness and response efforts. As the storm made its way towards the coast, residents and officials worked together to protect lives and minimize the potential damage from Hurricane Hilary.
0. “Hurricane Hilary brings historic warnings to California, flood watches to Oregon” Fox 12 Oregon, 19 Aug. 2023, https://www.kptv.com/2023/08/19/hurricane-hilary-brings-historic-warnings-california-flood-watches-oregon
1. “Governor Newsom Proclaims State of Emergency As Hurricane Hilary Approaches California | California Governor” Office of Governor Gavin Newsom, 20 Aug. 2023, https://www.gov.ca.gov/2023/08/19/governor-newsom-proclaims-state-of-emergency-as-hurricane-hilary-approaches-california
2. “Hurricane Hilary speeds toward California with “catastrophic” flooding” Axios, 19 Aug. 2023, https://www.axios.com/2023/08/19/hurricane-hilary-california-catastrophic-flood-nevada-arizona
3. “Hurricane Hilary updates: Live coverage as storm hits AZ, CA” The Arizona Republic, 18 Aug. 2023, https://www.azcentral.com/story/news/local/arizona-weather/2023/08/18/hurricane-hilary-rain-storm-updates-arizona/70623192007/
4. “County warns residents to prepare for upcoming storm, free sandbags available – Welcome to San Bernardino County” San Bernardino County (.gov), 18 Aug. 2023, https://main.sbcounty.gov/2023/08/18/county-warns-residents-to-prepare-for-upcoming-storm-free-sandbags-available/
5. “Hurricane Hilary live updates: Catastrophic flooding expected in Southwest” ABC News, 20 Aug. 2023, https://abcnews.go.com/US/live-updates/hurricane-hilary/?id=102393064
6. “Hurricane Hilary downgraded to Category 1; “potentially historic rainfall” could still occur” CBS News, 20 Aug. 2023, https://www.cbsnews.com/losangeles/news/hurricane-hilary-shifts-to-category-1-potentially-historic-rainfall-could-still-occur/
7. “Gov. Newsom declares state of emergency for southern California ahead of historic Hurricane Hilary” CNN, 20 Aug. 2023, https://www.cnn.com/2023/08/19/weather/hurricane-hilary-california-southwest-tropical-storm-saturday/index.html
8. “Hurricane Hilary will bring rainfall and flooding to Southern California” NPR, 19 Aug. 2023, https://www.npr.org/2023/08/19/1194684510/hurricane-hilary-prompts-flood-watch-from-mexico-to-north-of-los-angeles
