A powerful winter storm is expected to sweep across California’s Sierra Nevada this weekend, bringing heavy snowfall, strong winds, and dangerous travel conditions to some of the region’s most important mountain highways.

"Travel could be very difficult to impossible," the NWS said. "Strong winds could cause damage to trees and power lines."

The National Weather Service in Sacramento has upgraded the Winter Storm Watch to a Winter Storm Warning for the West Slope Northern Sierra Nevada and Western Plumas County,

On Wednesday at 2:50 p.m. a winter storm watch was issued by the NWS Hanford CA valid from Friday 5 p.m. until Sunday 11 p.m. The watch is for Yosemite, Upper San Joaquin River, Kaiser to Rodgers Ridge,

A strong spring storm will blanket the Sierra with a heavy snowfall, making travel difficult.

The forecast for the festival's second weekend looks similar.

El Niño is the warming of the sea surface temperatures thousands of miles away from the Bay Area in the Equatorial Pacific.

Many of the state's resorts have closed for the season, but powder will fall on places like Palisades Tahoe and Mammoth.