Stormy Weekend Ahead: Two Systems to Bring Widespread Rain, Thunderstorms to Southern California

A pair of upper-level low pressure systems will move through the state Friday through Monday, bringing rounds of rain, a chance of thunderstorms, and mountain snow, the National Weather Service said.

Showers could begin as early as Thursday night, with the most impactful weather expected late Saturday into Sunday.

Rainfall totals are expected to range from about 0.50 to 1.50 inches, with higher amounts in the mountains and foothills and in spots that experience thunderstorms. Thunderstorms are possible Saturday night into Sunday and could produce heavy downpours, lightning, small hail, and locally gusty winds.

Forecasters say an isolated waterspout or a small tornado cannot be ruled out. Peak rain rates are expected to range from 0.25 to 0.50 inches per hour, with isolated stronger storms up to 0.75 inches per hour.

Several inches of mountain snow are likely, with up to 6 inches possible above 6000 feet and higher totals above 7000 feet. Snow levels will lower Sunday night into Monday to around 4500–5000 feet.

Over the Grapevine, there is a 10–20% chance of a light dusting late Sunday into early Monday; flurries or a rain/snow mix are possible Monday morning, though the odds of accumulation are low.

The first system, centered near Northern California, will mainly affect areas north of Point Conception and bring mostly light showers to the Central Coast Friday into early Saturday, with most locations seeing less than a quarter inch. An isolated thunderstorm is possible in San Luis Obispo County.

The second system arrives later Saturday into Sunday morning with much colder air aloft and a higher chance of thunderstorms across the region, including south of Point Conception, along with the risk of small hail and gusty winds.

As the upper low moves through Monday morning, scattered showers will linger, snow levels will be lowest of the event, and Los Angeles County could see showers into the afternoon if the system exits slowly. Drying is expected Monday night, followed by a trend toward dry and warmer weather for the rest of the week.

Travelers should plan for changing conditions and possible delays, especially from Saturday night through Monday morning. Never drive through flooded roadways, as heavy downpours can quickly reduce visibility and cause water to pond on roads.

If you hear thunder, move indoors and off open water and beaches. Mountain travelers should check chain requirements, carry winter gear, and be prepared for rapidly changing conditions. Check the latest forecasts and road conditions, and follow updates from the National Weather Service and transportation agencies for any advisories or closures.