For 10 minutes, late Thursday morning, residents in part of North County were told to take cover for a possible tornado.
The National Weather Service in San Diego issued the warning at 10:21 a.m. for Valley Center, Escondido and Hidden Meadows, but the warning expired at 10:30 a.m. The agency said a severe thunderstorm over Valley Center that was moving rapidly east could produce a tornado.
"We decided to issue that tornado warning just based on that weak rotation that we saw on the radar," NWS meteorologist Adam Roser said. "But then, you know, kind of a short-fused warning too. Only about 10-15 minutes, so, made it short and sweet there."
Forecasters said a low-pressure system off the coast of California pushed rain into the region on Wednesday and drove the strong storm cells inland Thursday.
Officials at the Valley Center Middle School said they got the warning and kept their students away from the windows until the storm passed.
One resident said the sky just got dark around 10:30 a.m. and then the precipitation started to fall.
“A lot of very, very, cold hail and water. And a downpour probably for 10-15 minutes and then it slowed down and then came the second round again,” said Joe Villalobos of Joe's Country Feed and Pet Store in Valley Center.
The warning came roughly a week after an EF1 tornado touched down in Montebello, a suburb of Los Angeles. One person was injured. A weaker tornado also hit the city of Carpinteria in Santa Barbara last week.
"They're very rare but they do occur here in Southern California," Roser said. Contrary to popular belief, tornadoes don't just happen in the great plains, he said.
The last time the NWS issued a tornado warning in San Diego was January 2016 in the Poway and La Jolla areas, Roser said.
Since late December, there have been at least 13 atmospheric rivers that brought violent wind, rain and snow to California following years of drought.
