Northern California spring storm brings lightning in Sacramento, Sierra snow

By Richard Ramos

A spring system is bringing rounds of rain and thunderstorms to Northern California and continues through the weekend, including bringing snow to the Sierra.

Thunderstorm activity picked up by Friday afternoon, with a Tornado Warning issued for the Escalon and Farmington area of San Joaquin County. The Tornado Warning expired at 2:45 p.m.

Storm hazards across the valley include gusty winds, brief heavy downpours, lightning and small hail, along with the potential for slick roads and ponding on area roadways.

Numerous downed trees was reported Saturday night across the Sacramento area. Thousands of Sacramento Municipal Utility District customers across the area were without power.

Snow dropped Saturday night to around 3,500-4,000 feet. A winter storm warning is in place through Sunday evening and chain controls are expected over Donner Summit.

The unsettled pattern will continue into the weekend, when a more organized system moves through Northern California.

The CBS News Sacramento First Alert Weather team says multiple squall lines are expected to push onshore, with Saturday evening shaping up as the main event. That system could bring periods of heavy rain, poor drainage, flooding and embedded strong thunderstorms across the Sacramento Valley and surrounding areas.

The same system is expected to bring rain and heavy winds across the San Francisco Bay Area, with roughly three-quarters of an inch of rain possible throughout Saturday evening.

Thunderstorms are also likely in the Bay Area during this time, but early Sunday morning will bring an increased chance of that as the center of the system moves east over the region.

As the system moves into the Sierra Nevada, conditions are expected to develop quickly. Snow levels are forecast to drop quickly, leading to significant winter weather impacts.

Around 2 feet of snow is likely near Donner Pass, with up to 4 feet possible at higher elevations. Snow could also accumulate at lower elevations, with 2 to 6 inches possible down to about 4,000 feet.

Up to two inches of rain is expected across the valley floor, while as much as five inches could drench areas of the foothills like Grass Valley.

Waves of heavy rain and mountain snow are expected to continue through Sunday, before conditions begin to improve as the storm system exits the region.