The biggest storm in the western United States since this past winter will press inland with disruptive rain, snow and winds through Saturday.
Winds will be strong enough to cause tree and power line damage. The rain and mountain snow will be heavy enough to trigger flooding, mudslides and major travel disruptions.
Wind gusts to 70 mph will stir up seas and cause erosion along the coasts of Northern California to Washington. Gusts to 60 mph are anticipated farther inland across Oregon, Nevada, California, Washington and eventually Utah and Arizona.
“Rainfall amounts of 3 to 6 inches are expected across the Coastal Range and foothills of the Cascades and Sierra Nevada,” AccuWeather Meteorologist Jordan Root said.
Wind-swept rain will cause reduced visibility and slow travel along Interstate 5 from Sacramento, California, to Seattle.
“Additional water from melting snow in the mountains will lead to quick stream and river rises and possible flooding in some locations,” Root said.
Motorists should turn around and find an alternate route if a flooded road is encountered to avoid a life-threatening situation.
It is not out of the question for a few thunderstorms containing small hail to be embedded in the rain across central and Northern California, western Washington and northern Idaho.
The heaviest rain will fail to reach Los Angeles and San Diego, though spotty showers into Saturday morning could lead to slick roadways.
“Snow levels will fall through Saturday, with the heaviest snow occurring across the Sierra,” Root said.
Lowering snow levels caused snow to quickly stick on Interstate 80’s Donner Pass on Thursday night. The intensity of the snow will make it difficult for crews to keep roads clear into Saturday.
Gusty winds and heavy snow, leading to blizzard conditions at times, could make travel impossible and force road closures.
“Gusty winds will follow the rain in parts of Southern California and will kick up dust over the deserts well inland this weekend,” AccuWeather Senior Meteorologist Alex Sosnowski said.
Stretches of Interstate 8, I-10, I-15 and I-40 in California, Nevada, Utah and Arizona will be buffeted by the high winds.
Motorists should be mindful of this threat and be prepared to reduce speed in areas of blowing dust and reduced visibility.
After a much weaker storm aims at the Northwest late this weekend into early next week, it will take until next Thursday and Friday for the next major storm to impact the region.
The wet weather will continue to add to the rainfall surpluses since the beginning of the year, which has completely eliminated the drought in Northern and central California. A small area of moderate to severe drought remains from Santa Barbara County to San Diego and Imperial counties in Southern California.