Monster storm barrels into Northern California; woman killed by falling tree amid heavy winds

Atmospheric rivers are key to California's rainfall.

The strongest part of a series of storms barreled into Northern California on Sunday, bringing flooding, heavy snow and concerns about avalanches.

Officials reported scattered flooding and mudslides throughout the region, including a washed out road in Windsor that required the rescue of two people. Local authorities were watching rising water levels at several key rivers including the Truckee, Merced, American and Russian.


An "extreme" avalanche warning was issued for parts of the Sierra Nevada Mountains Sunday because of heavy snow. In Mammoth Lakes, officials said higher elevations recorded 48 inches of snow in the last two days.

Winds topped 50 mph in some areas. A woman was killed in the East Bay suburb of San Ramon on Saturday when she was struck by a falling tree at a golf course amid heavy winds.

Up to 12 inches of rain is expected to fall on areas below 8,500 feet beginning Saturday morning, and up to 7 feet of snow could bury higher elevations, according to the National Weather Service. Forecasters said the storm was packing the same wallop as one that hit Northern California in 2005, causing $300 million in damage.

This weekend's system could bring 36 consecutive hours of heavy rain from Mammoth Mountain to Susanville, in Lassen County. Though that is good news for California, which is entering its sixth year of drought, the coming rain could melt already standing snow — feeding watersheds swollen from storms earlier this week, forecasters said.

"It's going to be a busy weekend," said Edan Weishahn, a meteorologist with the National Weather Service in Reno, sighing.

The rain moved in late Friday and continued into Saturday morning, with the most powerful punch expected later in the day.

In the eastern Sierra Nevada, snow continued to fall at higher elevations while rain drizzled lower down as officials warned that wetter, rainier conditions on tap for later this weekend could spell trouble.