A cozy Christmas morning gave way to a wet and stormy afternoon Tuesday, with trees falling and cars crashing throughout the region.

A six-car crash on Highway 37 near the Fresh Air Bridge left four people with minor injuries.

Slippery streets led to several spinouts on Highway 101, including one in Windsor in which two cars collided. There were no serious injuries, a CHP dispatcher said.

The brunt of the storms passed through by early evening, sweeping south through the Bay Area, said Diana Henderson, forecaster with the National Weather Service.

"We haven't had much wind with this, it's just an awful lot of water that came down," Henderson said. "But unfortunately, it's been water on top of a lot of water. If you live near a creek, it can be a concern."

Floodwaters rose as high as 18 inches on Valley Ford Road near Highway 1 west of Petaluma, a CHP dispatcher said. By 6 p.m., just under an inch of rain had fallen in 24 hours in Petaluma, and rainfall totals hovered around the inch mark throughout the county.

In the Sierra, light snow and freezing fog at about 5,000 feet in the Blue Canyon area along Highway 80 were expected to make driving difficult. Visibility was limited to a quarter-mile, meteorologist Bob Benjamin said.

Light and intermittent showers may linger around the North Coast today. Thursday is likely to be the driest and chilliest day, with frost and freezing possible in deep valleys, Benjamin said.

Temperatures will be cool, with daytime highs in the 50s dropping down to the low 30s at night through the week, Benjamin said.

The next rainstorm is forecast to arrive Friday afternoon and linger through Saturday.