The National Weather Service (NWS) said that winter weather advisories are in effect for California's Sierra Nevada through Tuesday afternoon as a storm moving in from the Pacific brings "moderate snow showers" to the region.
Snow is expected in elevations above 6,000 to 6,500 feet, mainly on Tuesday afternoon, with up to 3 inches expected in some locations, the NWS said.
Periods of snow are expected to accumulate on area roads; snow accumulated Monday at Donner Summit on Interstate 80, the NWS said.
"Slippery conditions are expected at Sierra passes," forecasters said. "Travel delays and chain controls are possible."
Further east, snow is falling across parts of Nevada in Eureka, Pinto Summit, Garden Pass, and Tonopah.
A winter weather advisory is in effect until 11 a.m. local time, where up to 6 inches of snow may fall at the highest elevations in southern Lander and Eureka counties and in northwestern Nye County. Forecasters said that snow is even falling in valley areas.
"Expect snow-covered roads and limited visibilities, and use caution while driving," the NWS said.
The storm system also caused flash flood watches for the Sacramento Valley and the northern San Joaquin Valley. Wind advisories were in effect for the western San Joaquin Valley and planned for the interior mountains of Southern California.
Forecasters from the NWS' Weather Prediction Center (WPC) said the system is bringing "significant rains" to the Northwest and Northern Rockies also, leading to flood threats.
The Associated Press contributed to this report.