SAN FRANCISCO (AP) — Winter roared back into California on Tuesday after taking an almost summerlike break over the holiday weekend with warm and dry conditions that drew residents to beaches.

The first in a week of storms brought powerful winds, rain and snow to the state, substantially lowering temperatures that topped 80 degrees (26.6 Celsius) in some areas over Christmas.

There were numerous reports of roadway flooding and downed trees and branches as the storm blew into the northern half of the state and spread south, the National Weather Service said.

Pacific Gas & Electric’s website showed numerous power outages scattered across Northern California.

Winter storm warnings were issued for the Sierra Nevada, where motorists were advised that travel could be hazardous. Chains or snow tires were required on some highways.

Gusts up to 120 mph (193 kph) were recorded on some Sierra ridgetops, the Reno, Nevada, weather office said. Backcountry avalanche warnings were issued for parts of the mountain range.

The weather system, an atmospheric river spawned by a low pressure off the Pacific Northwest, was spreading slowly down the coast and was expected to reach Los Angeles by evening.

State Department of Water Resources data show that drought-stricken California’s mountain snowpack, a third of the state’s water supply, is off to a good start after a wet fall and early winter — 145% of normal to date and 45% of the April 1 average, when it is normally at its peak.

But experts remain cautious. Last winter had a similar start and then turned extraordinarily dry January through March.