Winter Weather Advisory: Sierra Nevada travel troubles and Southern California mountain snow

Back-to-back storms dumped up to three feet of snow in parts of the Southern California mountains, creating icy roads and chain requirements that have disrupted travel across the Sierra Nevada. The combination of heavy snowfall, level 2 chain requirements and clearing skies that bring colder overnight lows means conditions match a winter weather advisory for drivers heading into mountain areas.

Winter Weather Advisory and travel impacts

Areas such as parts of the San Bernardino Mountains saw up to three feet of snow over recent days, leaving many mountain roads icy and treacherous. The situation has produced widespread traffic impacts and travel trouble reports across the Sierra Nevada. Some motorists attempting to drive into affected areas were turned away at roadway checkpoints, and many others found themselves needing to fit tire chains on the roadside.

Chain requirements and road rules

All mountain roads are under a level 2 chain requirement: chains or traction devices are required for all cars except vehicles with four-wheel drive or all-wheel drive equipped with four snow-tread tires. Even exempt vehicles must still carry chains in case conditions worsen. Enforcement on mountain approaches has meant some drivers without appropriate gear were prevented from proceeding. Motorists who lacked chain experience were forced to learn the skill in place while officers managed traffic flow.

Sierra Nevada travel troubles and what to expect

Clearing skies following the storms will lead to colder overnight lows and raise the risk of black ice on treated and untreated surfaces. Driving at about 25 mph is recommended where icy conditions persist. Travelers planning mountain trips are advised to carry extra water, food and blankets in case they become stranded or delayed. The combination of recent heavy snowfall, active chain controls and overnight freezing conditions is the core cause of the current travel disruptions across mountain corridors.

Key takeaways:

• Up to three feet of snow fell in parts of the San Bernardino Mountains.
• All mountain roads are under a level 2 chain requirement; some drivers have been turned away.
• Clearing skies will bring colder nights and increase black ice risk; driving 25 mph is recommended.