Residents of Northern California were hunkering down early Sunday as a powerful storm drenched the area with yet another round of pounding rain and strong winds.
The latest storm system moved into the region Saturday night and was expected to force several Northern California rivers over their banks.
The Napa River, north of San Francisco, a river with a history of flooding, was expected to top its banks some time Sunday afternoon.
The Russian River, another river that frequently floods was expected to flood near the Sonoma County community of Guerneville Monday morning.
"Some roads will become inundated and some of the agricultural areas will take on some water," said Mark Strudley, a hydrologist with the National Weather Service.
The Napa River overwhelmed downtown Napa in 2005, flooding or destroying about 1,000 homes and forcing thousands of residents to leave the area.
With that in mind, residents worked to fill 700 bags with 10 tons of sand, city official Danny Lerma said.
"When you see it happen, you always remember, and you say, 'I'm going to be better prepared,'" Lerma told KGO-TV. "And that's what they're doing right now."
Farther north, forecasters said the Truckee River near Lake Tahoe was expected to crest above flood level by Sunday morning. The threat of flooding prompted officials in Truckee, a small town of about 16,000, to set up an evacuation center.
A flash flood watch was also in effect for a wide area of Northern California through Sunday evening.
To the south, forecasters say as much as one inch of rain per hour fell on parts of the Santa Cruz mountains early Sunday, prompting the National Weather Service to issue a flash flood warning for parts of Santa Cruz and Santa Clara counties.
CBS Station KOVR reports residents near the Truckee River are bracing themselves for rain the region hasn't seen in possibly a decade or more.
"It's a little surreal. Here we are standing here, and all this water's going to come overnight," said Rick Reynolds, who lives near the river.
Reynolds lives just yards from the rushing water that's expected to come up possibly four feet over floor level, creeping closer to his home.