(CBS/AP) – A massive winter storm that walloped the Sierra Nevada with blizzard conditions is bringing powerful thunderstorms and dangerous surf to Southern California.

A section of Interstate 80 in the Sierra was closed due to blizzard conditions, and Caltrans crews shut a section of the highway over Donner Summit late Sunday for an unknown duration.

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The seven-day total could approach 20 inches of rain in Northern California and up to three inches in the southern end of the state.

Local Forecast

Light showers are still possible for valley for Monday during the morning commute. Heavier rain is moving into the foothills, and very heavy snow continues in the mountains. The Bay Area and Central Valley will generally see a break in the rain beginning later Monday morning. Isolated thunderstorm are a threat today; precipitation continues at higher elevations through this evening:

A storm warning is in effect until 4 p.m. Monday.

Snow Totals
• Blue Canyon has seen 18” of snow just since Sunday afternoon.
• Snow was falling at a rate of 1-2” per hour Monday morning.
• An ADDITIONAL 4-8” of snow expected Monday morning.
• The snow level is at 3,500-4,500’.


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Valley: 2-4” Rain
Foothills: 4-7” Rain

5,000’: 18-24” Snow
Crest: 4 ft. Snow

The National Weather Service is warning of possible flooding in Southern California Monday as heavy rains along with thunder and lightning move through the greater Los Angeles area.

Flash flood watches are in place for foothill neighborhoods underneath wildfire burn areas, triggering fears of possible mudslides.

Snow was expected at the 5,000-foot level in mountains in Los Angeles and San Bernardino counties.

Up to two inches of snow per hour was predicted overnight for the Sierra Nevada, where drivers were warned of whiteout conditions.

Authorities in Yuba County said a woman died over the weekend after being trapped in a car that became submerged in floodwaters on a section of highway that was closed amid heavy rain.

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