Snow levels are expected to plummet to around 3,000 feet by tonight, potentially impacting travel for motorists, and the National Weather Service has released a winter weather advisory through 10 a.m. Friday.

A wet Pacific storm will bring snow to the mountains today, with snow levels starting around 6,000 to 7,000 feet, according to the advisory. They are expected to drop to 3,000 feet by tonight.

"This will impact travel over the passes in the Cascade and Siskiyou mountains Thursday night and Friday," the advisory said. "There will be a break on Saturday, but another storm is expected to impact the mountains Sunday into early next week."

Snow accumulations could be as high as 7 inches, with more than a foot possible for the higher peaks. The heaviest snowfall is expected between 4 and 10 p.m.