A strong winter storm lashed at Southern California on Thanksgiving, disrupting travel plans on one of the busiest days of the year.

Heavy snow shut down Interstate 5 through the Grapevine in the Tejon Pass this morning. The major north-south freeway was closed at 4:30 AM, but even prior to that, California Highway Patrol had to assist motorists to get through the steep area. Authorities were suggesting motorists try the 101 North as an alternate route, as there was no indication that the I-5 would reopen soon.

Several roads in the Angeles National Forest were also closed by snow.

The National Weather Service had a winter storm warning out for Los Angeles, Ventura and Santa Barbara counties that will remain in place through 4 AM on Friday. Heavy snow was falling in the Antelope Valley, including Palmdale and Lancaster.