Whiteout conditions possible in the Sierra; widespread rain likely across Bay Area this week

A fairly potent storm system is expected to hit Northern California early this week — likely dropping more rain over the Bay Area than any point since April, while supplying the Sierra Nevada with a healthy coating of powder.

Low-lying parts of Bay Area — including Oakland, San Francisco and San Jose — could receive 1 to 1.5 inches of rain from late Sunday night through Wednesday, while the coastal ranges could get up to 3 inches of fresh precipitation, according to the National Weather Service. To the east, areas of the Sierra above 4,000 feet can expect one to four feet of snow, potentially offering ski resorts a chance to begin loading up with powder ahead of the Thanksgiving holiday rush.

The direly-needed precipitation is owed to an upper-level low pressure system that is expected to move over Northern California over the next couple days.

The first wave of rain is expected to arrive late Sunday afternoon over the North Bay and over the northern reaches of the Peninsula and the East Bay, before sweeping south to San Jose shortly before midnight Sunday. Another wave of heavier precipitation is expected to hit early Tuesday morning.

The system could produce thunderstorms on Monday and Tuesday over the Bay Area, along with “copious” amounts of hail that could make travel hazardous, said Roger Gass, a National Weather Service meteorologist.

Over the Sierra, the first flurries are expected to begin falling Sunday night and continue through at least Tuesday. At times, the snow could fall at a rate of 1 to 3 inches an hour — creating whiteout conditions, especially when coupled with winds that are forecasted to reach 45 to 55 mph, said Hannah Chandler-Cooley, another National Weather Service meteorologist.

“We are highly discouraging travel over the mountains over this time period,” Chandler-Cooley said.