A fierce storm is sweeping through the US state of California, unleashing rain, wind and snow, and cutting power supplies and transport links.
Up to 10ft (3m) of snow is expected in the Sierra Nevada mountains, as blizzards forced ski resorts to close and drivers were warned off roads.
Heavy rains threatened to trigger mudslides in canyons already scarred by last year's wildfires.
The extreme weather could last through the weekend, forecasters say.
There have been no reports of injuries or deaths so far.
The storm began lashing the north of the state on Thursday, with thousands of residents from the Bay Area to the central valley suffering power cuts.
Large vehicles have been banned from San Francisco's Golden Gate bridge, where winds gusted at 55mph (90km/h).
Further south, a storm was gathering off the coast and was expected to hit land by Saturday afternoon.
In fire-hit areas, residents piled sandbags around their homes to protect them from possible mudslides.
Voluntary evacuations were being organised in the Modjeska and Silverado canyons, where 15 homes burned down in the autumn.
Tides are expected to rise to 30ft, and all Pacific Ocean-going vessels are being urged to remain in port.
Meanwhile Florida was hit by a cold snap, although citrus growers said the freeze did not last long enough to seriously affect crops.
The weather difficulties come just 10 days after snow storms from the Great Lakes on the border with Canada down to Texas left 22 people dead and tens of thousands without electricity.