Tropical Storm Hilary: Preparation pays off for California
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Ali Martin Staff writer
| Bakersfield, Calif.
A rare tropical storm moved through California over the weekend, bringing record rainfall, high winds, and mudslides. Despite extreme precipitation and winds of up to 80 mph, catastrophic damage was avoided 鈥� in part due to successful preparation efforts honed from years of extreme weather events in the state.聽
At least 20 million people 鈥撀爉ore than half of California鈥檚 population 鈥撀爓ere affected by Tropical Storm Hilary, which dropped a year鈥檚 worth of rainfall in one day, and in some areas two years鈥� worth. Hilary made landfall in Mexico on Aug. 20, swept north through Southern California, and then dissipated in southern Nevada. No deaths were reported in the United States; one person died in Mexico.聽
State, county, and local officials in California quickly mobilized residents and resources, issuing evacuation orders, detailing safety reminders, and providing sandbags ahead of the storm. Efforts were guided by high-tech and highly accurate meteorological predictions, and aided by the storm鈥檚 natural dissipation.聽
Why We Wrote This
California鈥檚 familiarity with disaster preparation, born of many experiences with storms, wildfires, and earthquakes, helped ease the impact of rare Tropical Storm Hilary.
鈥淚t is a good outcome for a storm of this magnitude,鈥� says Brian Ferguson, deputy director of crisis communications for California鈥檚 Office of Emergency Services, who suggests that California鈥檚 disaster approach could be modeled elsewhere.
鈥淲e have invested a lot in technology and first responders and being on the front foot in disasters,鈥� says Mr. Ferguson. 鈥淎nd I think those are tools that we鈥檒l take for other disasters here in the state, but could also be replicated elsewhere in the country.鈥�
Tropical storms are rare in California. How did Hilary happen?聽 聽
Tropical Storm Hilary was born of an El Ni帽o warming up waters in the Pacific Ocean, and a heat dome covering the Midwest. The warm water and warm, circulating air intensified the storm 鈥� which, at one point, was a Category 4 hurricane 鈥� and drew it inland from off the coast of Mexico鈥檚 Baja California Peninsula.
鈥淥therwise, she would have done a normal thing, which is to go across the ocean to our west or maybe turn and go into Mexico and fizzle out there,鈥� explains Alex Tardy, senior meteorologist with the National Weather Service鈥檚 San Diego station.
California鈥檚 last tropical storm, Nora, was in 1997. Before that was , which was also the last tropical storm to pass over Los Angeles. Dozens of people died in the 1939 storm.聽
Hilary arrived during what鈥檚 normally the driest month in this drought-sensitive state. The storm鈥檚 impact ranged from heavy rain in some areas to wind and mudslides that took out major infrastructure.
How did preparation efforts help mitigate damage?聽
Californians are used to preparing for disasters. Complex, overlapping events such as drought, fire, rain, snow, and earthquakes are a reality of living here, says Mr. Ferguson. 鈥淲e even had an earthquake in the middle of this hurricane,鈥� he says. 鈥淲e don鈥檛 have one disaster at a time.鈥澛�
Meteorological predictions for Hilary, including聽the storm鈥檚 estimated rainfall and path, were on target, giving residents and officials five days to prepare before the storm reached San Diego. State, county, and local emergency management offices coordinated preemptive measures.
Among the actions taken: First responders were mobilized ahead of the storm, with National Guard and swift-water rescue teams, firefighters, road crews, and utility crews sent to areas expected to be impacted. Residents living near burn scars were asked to evacuate. Unhoused people staying in high-risk areas were relocated. Cities gave out free sandbags so residents could protect their homes. California鈥檚 two largest school districts closed for a day.聽
Even with the prep and warnings, the storm stranded a number of people and forced rescues throughout Southern California, especially in rural parts of San Bernardino and Riverside counties east of Los Angeles. And as of Tuesday, an older woman whose home was swept away by a mudslide was still missing.
Nearly 50 people were rescued from flooded streets near Palm Springs in Cathedral City, where the Red Cross was called in to help. And farther south, more than a dozen people were rescued from a homeless encampment in the San Diego River basin.聽
Experts and officials agree the toll could have been much worse. California鈥檚 varied topography results in a steady stream of weather events and related disasters 鈥撀爀xperiences that 鈥減robably made us more prepared to handle an event like this because of the work that鈥檚 happened and the public鈥檚 understanding of what goes into a disaster and how to keep themselves safe,鈥� Mr. Ferguson says.聽
How does Hilary fit with other extreme weather in California?聽
California endured , , and in 2023, after three of the on record. Wildfires have burned about 320,000 acres throughout the state this year, which is less area than the five-year average 鈥撀燽ut large fires are happening more frequently.聽
The San Bernardino Mountains, next to the desert resort area of the Coachella Valley, had more snow than ever in late February and early March; July was the hottest month ever recorded in Palm Springs.
During this weekend鈥檚 tropical storm, the Coachella Valley, which includes Palm Springs, received the worst storm damage, with rainfall ranging from 3 to 5 inches on the valley floor, and from 8 to 13 inches in the upper mountain headwaters, which drain into the valley. The heavy rain, combined with high winds in the surrounding mountains, caused mudslides that shut down Interstate 10, made rail lines impassable, and damaged homes and other infrastructure.
Hilary may not have a direct link to any one previous extreme weather event, explains meteorologist Mr. Tardy, but collectively, they show a clear trend. 鈥淛ust the sheer magnitude of these events appears to be hard to argue that it鈥檚 not related to the overall warming of the planet,鈥� he says. 鈥淲e鈥檙e taking normal events and making them a little more harsh, a little more extreme, a little more impact.鈥�
