UPDATE (7:45 a.m.): California Highway Patrol officials say chain requirements are in effect for vehicles traveling on the following roadways:
-- SR-79 at Mile Post Marker 5.5
-- SR-79 at SR-478
-- Sunrise Highway at Olde Highway 80
CHP officials are reminding drivers with four-wheel drive vehicles to carry chains.
SAN DIEGO (CNS) – A cold winter storm drenched San Diego County with rain Thursday, but the storm also dumped snow on the county's mountains, prompting five area school districts to cancel classes.
The county Office of Education said campuses in the Julian Union School District, Julian Union High School District, Mountain Empire Unified School District, Spencer Valley School District and Warner Springs Unified School District are closed Thursday and Friday due to inclement weather.
The National Weather Service issued a winter storm warning that remains in effect until 1 a.m. Friday for the local mountains. As of Thursday afternoon, 10-14 inches of snow had fallen on Big Bear Lake, with more expected through early evening, forcing the closure of several roads.
Highway 18 from the SR-330 junction near San Bernardino to Big Bear Lake is closed, according to CalTrans. Alternative routes on Highway 38 from Redlands and Highway 18 from Lucerne Valley were also closed Thursday until crews could clear them before the weekend.
NWS officials warned that the icy conditions and considerable snowfall will make travel to those locales hazardous over the period.
"If you must travel, keep an extra flashlight, food and water in your vehicle in case of emergency," the weather service warned.
Snow levels will drop to around 3,000 feet by Thursday night, according to the NWS.
As of Wednesday evening, Palomar Mountain had received around 3 inches of snow. Other snowfall totals were not immediately available.
From Wednesday evening through Thursday night, the storm could drop up to a foot of snow near the top of Mount Laguna as well as Cuyamaca Peak and up to 8 inches in Julian, the NWS said.
The south-moving storm will continue to douse the county with periods of showers continuing until late Thursday night, forecasters said.
In a 24-hour period ending around 3 a.m., Descanso had the highest precipitation total, with 1.35 inches, followed by 1.28 at the Hensaw Dam; 1.13 in Mesa Grande and Pine Hills; 0.87 in Alpine; 0.84 at Skyline Ranch; 0.81 in Warner Springs, 0.76 in Pine Valley; 0.66 in Poway and Harbison Canyon; 0.63 in Valley Center; 0.55 in Santee; 0.51 in Barona and 0.45 in La Mesa and Ramona, according to the National Weather Service.
Other rainfall totals around the county included 0.42 of an inch at Brown Field; 0.38 in Kearny Mesa; 0.32 in Fallbrook; 0.31 in San Ysidro; 0.26 in Escondido; 0.23 at Fashion Valley; 0.20 in San Felipe and 0.10 at Lindbergh Field.
The storm is expected to bring around a half-inch of rainfall to coastal areas on Thursday, anywhere from a half-inch to an inch to inland-valley areas, 1 to 1.5 inches in the mountains, and one-quarter to three-quarters of an inch in the deserts, forecasters said.
Sunny skies are expected Friday, but temperatures will remain well below average because the region remains under a cold air mass, NWS meteorologist Miguel Miller said.