Hurricane Hilary prompts flood watch from Mexico to north of Los Angeles
Updated August 19, 2023 at 11:19 AM ET
Flood watches are in effect from Mexico, north to Ventura, and inland to western Arizona, as torrential rains from what remains of Hurricane Hilary are expected to impact the West Coast and Southwest through the weekend.
The hurricane was downgraded to a Category 3, with maximum sustained winds of 125 mph, the National Hurricane Center said in its 11 a.m. ET advisory Saturday.
Most of the storm's energy is predicted to cross north of the border with Mexico Sunday night into Monday.
Daniel Swain, a climate scientist at the University of California, Los Angeles, says some inland desert areas could see upward of 5 to 10 inches of rain.
"We're talking about the potential for multiple years worth of precipitation in just two days in some parts of the deserts of southeastern California, southern Nevada and western Arizona," Swain said.
Southern California is under its first-ever tropical storm watch as Hilary approaches.
National Weather Service meteorologist Alex Tardy in San Diego told KPBS the last time a hurricane entered San Diego County was 1858, and only a few named storms have ever done the same.
"1976, Kathleen. 1977, Doereen. 1997, Eudora," Tardy lists, "there's not many that we can look back historically that even had a forecast coming right at us."
There was one storm in 1939 that held its tropical storm strength until it got to San Diego, but that's it. This weather is very unusual for the region.
Forecasts call for heavy rain far inland, to places including Palm Springs and the Imperial Valley on the California-Arizona state line.
The National Weather Service says "flash, urban and arroyo flooding is expected, with the potential for rare and dangerous impacts."
KPBS environment reporter Erik Anderson says there's a lot of concern for this storm's impact on the city of Tijuana. It's a quickly growing city built on a hillside surrounded by canyons. Heavy rainfalls increase the chance of mudslides, which cause more problems and can be deadlier in Tijuana than San Diego.
Even though extreme storms are rare in Southern California, there are preparations in place. Anderson says many residents are already prepared for more frequent disasters like wildfires and earthquakes, and have plans in place if they need to leave.
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