California Weather Update: Warnings Issued as Atmospheric River Soaks State

Numerous weather warnings have been issued for California as the Golden State experiences a torrent of poor post-Christmas weather.

Why It’s Important

Widespread rain and stormy conditions are expected across much of California this week. The National Weather Service (NWS) has posted a slew of advisories, including flooding, surf, snow and wind warnings as an atmospheric river is set to drench the West Coast state just in time for the post-Christmas travel weekend.

Atmospheric rivers are long, narrow regions in the atmosphere that transport water vapor in from the Pacific Ocean. When atmospheric rivers make landfall, they typically release this water vapor as either rain or snow, at times causing heavy rainfall and possibly flooding.

The NWS said the “next rain maker is on the way and will move through the region” throughout Friday morning.

What To Know

Winter Weather Warnings and Advisories

Numerous winter weather warnings and advisories are in place, particularly in California’s northeastern areas.

Wet snow and additional accumulations of up to 5 inches are forecast for Plumas and Lassen Park counties until noon on Friday. The NWS warns motorists that there will be slippery conditions on roads, with travel delays and chain controls possible.

Lower elevations around Lake Tahoe will see around 4 inches of snow on Friday, which will be accompanied by gusts of up to 55 mph. Wet slushy roads are still possible across Donner Pass, Echo Summit and Mount Rose Summit, the NWS has warned.

Flood and Coastal Warnings

Flood advisories and/or warnings are currently active for the following locations:

• Sonoma
• Monterey
• Marin
• Mendocino

In Mendocino, floodwaters are currently at 15.0 feet, with flooding of Highway 175 expected at the approaches to the Russian River bridge, the NWS reports.

Some coastal areas are also subject to high surf advisories and beach hazards. Large waves up to 8 feet tall are expected along the Malibu Coast and Los Angeles County beaches, with the NWS warning of “an increased risk of ocean drowning,” as well as rip currents pulling even experienced swimmers and surfers out to sea.

The warnings follow the collapse of a 150 foot segment of a wharf in Santa Cruz due to high waves on Monday, and storm debris has been blamed in the death of a man at a beach in Watsonville.

Wind Warnings

Wind advisories and/or high wind warnings are currently in place in Plumas, Sierra, Mono, Modoc, Santa Barbara, and Ventura counties, as well the Sacramento Valley.

Wind gusts of as much as 60 mph are also expected along the Interstate 5 Corridor, which is likely to make driving difficult, especially for drivers of high profile vehicles. Similarly, travel along Highway 14 Corridor could be impacted by 50 mph winds.

What’s Next

Poor weather is likely to continue throughout the weekend as rain and snow continues, particularly in the northern reaches of the state. Rain and snow are expected through to around midnight on Sunday, maps from AccuWeather show.