California Hit by Early Winter Storms, Causing Snow and Road Closures

California experienced an early winter storm over the Halloween weekend, with snow blanketing the Sierra Nevada mountains and rain falling along the coast. Chain controls were put in place on Highway 88 due to accumulating snow and icy conditions.

Snow showers began Saturday morning in higher elevations of the Sierra Nevada. The National Weather Service Sacramento issued a Winter Weather Advisory for areas above 7,000 feet from Saturday morning through Sunday morning. By Sunday afternoon, several high-country passes, including Monitor Pass (State Route 89) and Sonora Pass (State Route 108), were fully closed due to snow accumulation, according to Caltrans QuickMap.

Forecasters predicted snow levels to range between 7,000 and 8,000 feet before lowering to 6,000 to 7,000 feet overnight. The high-country advisory expired Sunday morning, with the NWS Sacramento noting that precipitation was tapering off but warning of potential flurries down to 5,500 feet in areas south of Highway 50.

Motorists were cautioned about slush, ice, and reduced visibility on mountain passes, and advised to carry winter gear and check Caltrans QuickMap before traveling through high elevations. The NWS Sacramento noted that the precipitation marked a "damp end to October," with more light rain possible on Tuesday and Wednesday.

Meanwhile, a "Pineapple Express" atmospheric river system brought coastal rain and high surf to Southern California and the Desert Southwest over the holiday weekend. While major metropolitan areas saw lighter rainfall, south- and west-facing mountain slopes received up to three inches of rain, according to NWS San Diego. A Flood Advisory was issued for coastal Orange County due to concerns about minor urban flooding.

The storm systems were fueled by a southward plunge of the jet stream near the West Coast, according to senior meteorologist Jonathan Erdman of Weather.com. A secondary Pacific system was expected to approach Northern and Central California by Tuesday, bringing more cloud cover, lower snow levels, and additional mountain snow and valley showers.