It is not known how long State Route 38 will be closed, according to Caltrans.
Propelled by the jet stream, Friday's storm was expected to drop temperatures into the single-digits in the higher elevations, with the coldest spot being the zero degrees at Baldwin Lake, which borders Big Bear City, said Alex Tardy, a meteorologist with the National Weather Service.
An Friday overnight low of 10 degrees was expected at the top of the tram at Mt. San Jacinto, he said.
All schools in the Rim of the World Unified School District were closed Friday in advance of the winter storm.
Schools in the Bear Valley Unified School District were closed Friday, but that was due to "the law enforcement investigation and uncertainty about the whereabouts of Chris Dorner," according to the district's website.