Slight Chance of Thunderstorms Starts The Week For SoCal

While it’s been a warm and sunny start of the week for most of Southern California, there is a slight chance of thunderstorms, heavy rain, and even small hail through Monday night.

The chance of wet weather is expected to spread across Riverside and Orange counties in the afternoon, before moving into Los Angeles and Ventura counties until around 10 p.m. Monday.

A strong thunderstorm with more than 30 mph winds and “pea size” hail is expected to hit parts of O.C., including Fullerton, Newport Beach, and Fountain Valley, through 3:45 p.m., according to a severe weather statement issued by the National Weather Service.

Kristan Lund, a meteorologist with the National Weather Service, told LAist that it’s all being fueled by a low-pressure system that’s been lingering along the California-Arizona border for about a week now.

Thunderstorms? Again?

Lund said the upper-level, low-pressure system is causing instability in the atmosphere and bringing thunderstorms along with it.

“These thunderstorms could provide a lot of lightning, very locally-erratic and gusty winds, small hail, really brief to heavy showers, and then this will continue through the evening,” she said.

They could pop up anywhere from the mountains to the coast, Lund said, so you might want to consider a change of location if you have any plans outside.

Remember, when thunder roars, go indoors.

“You also want to wait at least 30 minutes after you last hear thunder before you even try to go outside again,” she noted.

If this feels familiar, that’s because it is. The same low-pressure system sparked a slight chance of storms for the region this past Friday, which led to a severe thunderstorm warning for Norwalk, El Monte, and Downey.

It had started out as an “inside slider,” Lund said, which is a system that moves down the coast but doesn’t go over the ocean so it misses a lot of moisture. However, this one has been sitting out over Arizona, occasionally wobbling west and toward Southern California.

“It kind of moved away a little bit, and then it's moving back a little bit today,” she said. “So that's why we're getting thunderstorms.”

Once the weather clears up Monday night, another slight chance of thunderstorms will be right behind it for Tuesday, but that’ll be more for the mountain and foothill areas of L.A. and Ventura counties.