A weather system that kicked into gear Thursday started bringing heavy snow to Oregon’s Cascade Range passes, while dropping smaller amounts in the Cascade Foothills and Coast Range.

The snow won’t reach Oregon’s valley floor, but it will come as close as any storm yet this season, weather officials said.

Latest KGW forecast

"The Cascade resorts have picked up at least half a foot of fresh powder since yesterday. In fact Timberline is reporting nearly 30 inches since Tuesday," said meteorologist Chris McGinness.

Snow showers will be on and off Friday with snow levels between 2,000 and 2,500 feet, McGinness said. "Snow levels will rise substantially by early Saturday morning, but not before we see a fresh 6-12 inches on the slopes and even more at higher elevations."

A Winter Weather Advisory is in effect for the Cascades until 10 a.m. Saturday.

The storm is the third in a series that’s brought relief to ski areas but made mountain roads dangerous, causing multiple accidents. But while the snow will create challenging conditions for drivers, it will continue to improve Oregon’s meager snowpack.

On the west side of Oregon, the snowpack has started to improve but still is just 40 to 50 percent of normal.

In addition to snow, forecasters said some flooding would be possible in northwest Oregon.

“Rivers are already running high from the rain this week, and soils are fully saturated,” the National Weather Service said in a statement. “Rainfall amounts Friday night through Saturday night could be as high as 5 inches in the Coast Range and Cascades and 2 inches for inland valleys.”