'Atmospheric river' dumps heavy rain, snow across California

SACRAMENTO, Calif. (AP) — A powerful storm brought drenching rain or heavy snowfall to much of California on Saturday, snarling traffic and closing highways as the state prepared to usher in a new year.

In the high Sierra Nevada, as much as 2 feet (0.6 meters) of snow could accumulate into early Sunday. The National Weather Service in Sacramento warned about hazardous driving conditions and posted photos on Twitter showing traffic on snow-covered mountain passes, where vehicles were required to have chains or four-wheel drive.

The so-called atmospheric river storm was pulling in a long and wide plume of moisture from the Pacific Ocean. Flooding and rock slides closed portions of roads across Northern California.

The California Highway Patrol said a section of U.S. 101 — one of the state's main traffic arteries — was closed indefinitely south of San Francisco because of flooding. Videos on Twitter showed mud-colored water streaming along San Francisco streets, and a staircase in Oakland turned into a veritable waterfall by heavy rains.

Weather service meteorologist Courtney Carpenter said the storm could drop over an inch of rain in the Sacramento area before moving south. One ski resort south of Lake Tahoe closed chair lifts because of flooding and operational problems, and posted a photo on Twitter showing one lift tower and its empty chairs surrounded by water.

“We're seeing a lot of flooding,” Carpenter said.

The Sacramento agency released a map of 24-hour precipitation through Saturday morning, showing a wide range of totals in the region, from less than an inch (2.54 centimeters) in some areas to more than 5 inches (12.7 centimeters) in the Sierra foothills.

The Mammoth Mountain Ski Area reported numerous lift closings, citing high winds, low visibility and...