A storm will bring a dose of chilly air, drenching rain, mountain snow and gusty winds to much of California, Arizona and Nevada this weekend.
Enough rain, snow and wind will occur to cause travel disruptions as people head home from their Thanksgiving and shopping activities.
First, pouring rain will spread southward over much of California on Saturday then push inland over the Southwest during the rest of the weekend.
Areas from San Francisco and Sacramento to Los Angeles and San Diego will get a thorough soaking. Enough rain can fall in these cities and other areas to cause minor urban flooding and raise the risk of mudslides in recent burn areas.
Several inches of rain will fall along the coast of northern California and Oregon with 1-2 inches over much of central California and 0.50 to 1 inch along the coast of Southern California.
The combination of rain and a low cloud ceiling can cause delays at area airports, including San Francisco and Los Angeles.
Spotty showers may survive the trip across the deserts and may briefly visit cities such as Palm Springs, California, Las Vegas and Phoenix.
The storm will bring along a considerable amount of cold air. High temperatures will trend downward from the 70s F on Friday to the 60s on Saturday and the 50s on Sunday around Los Angeles.
Snow levels will lower over the mountains as the weekend progresses and the chilly air settles over the region.
"Wintry travel will affect the passes in California and over the mountains in Arizona," according to AccuWeather Senior Meteorologist Henry Margusity.
California passes at risk for slippery conditions with snowcovered roads include Donner Pass, along Interstate 80, and Tejon Pass, along I-5. Travel may also be slippery over Siskiyou Summit, along I-5 in southern Oregon and over the higher terrain along I-40 in Arizona.
"Snowfall will range from a few inches over the passes to 1-2 feet over the high country of the Sierra Nevada and southern Cascades," according to AccuWeather Meteorologist Rob Miller.
From 6 to perhaps as much as 12 inches can accumulate over the Arizona mountains, Miller said.
The snow will be an early boon for ski resorts with a full season ahead.
Gusty winds accompanying the storm will cause blowing and drifting snow over the mountains and passes and rough seas and surf for a time along the coast.
Winds could become strong enough to be a problem for high-profile vehicles, such as trucks and RVs venturing through the passes.
Gusty winds will also kick up some dust over some of the deserts in southeastern California and southern Arizona, where little or no rain falls.
The rain and snow will bring some drought relief, although it will primarily bring short-term benefits.
In the wake of the weekend storm, cool air will remain entrenched over much of the region.
Temperatures into the start of December will range from a few degrees below average along the southern California coast to about 10 degrees below average over the interior Southwest.
The pattern will help set the stage for stormy conditions over much of the nation well into December.