UPDATE (2:31 pm PST) — A winter weather warning is in effect for the Portland metro area Tuesday, and the National Weather Service – and Portland Mayor Ted Wheeler – is advising people to stay home if possible.

About 3 to 8 inches of snow is expected in Portland, falling in line with much of the rest of the state where snowfall continues to remind Oregonians that winter is not over.

It’s also the first real test of the winter for local transportation agencies tasked with figuring out how to improve road conditions after a historic winter of abandoned cars and impassable roads last year.

The National Weather Service says snow will begin accumulating on roads when the sun goes down between 5:30 p.m. and 6 p.m. Tuesday, or when snowfall rates increase later in the afternoon.

“It’ll actually be a pretty snowy day across most of western Oregon,” said Matthew Cullen, a meteorologist with the National Weather Service in Portland.

“This first bit of snow is expected to be on the light side, and so far it has been. The next round of snow is the more steady and heavier snow; that’s still on track to move in later this afternoon.”

The Portland Bureau of Transportation has shifted to incident command mode, with crews working 12-hour shifts around the clock to clear the streets. About 55 snow plows have been deployed, and, for the first time, the agency is salting city streets.

“We need your help,” said Kimberly Dinwiddie with the Oregon Department of Transportation. “We have the staff, we have the equipment, and we have the tools to make the road safe… give us the room to clear the roads and consider delaying travel until road conditions improve.”

Photos of the late February 2018 snowstorm from around the Portland metro area.

Around the region, schools reacted to the weather by closing or dismissing students early Tuesday. Portland Public Schools released two hours early, while Beaverton School District closed all schools early. Portland Community College announced its campuses would be closed for the day. Find more school closings and delays here.

TriMet, the city’s transit agency, says it’s closely monitoring road conditions. Fifteen of its buses running in higher elevations are utilizing drop-down chains, slowing buses down to 25 mph.

Washington County and Multnomah County’s Joint Office of Homeless Service are among those who will open warming shelters Tuesday. Severe weather centers do not require personal identification or documentation. People are encouraged to call 211 for more information about health and social services in Oregon and Southwest Washington.

Statewide, it’s unlikely the snowfall will bring the below-normal snowpack back to normal levels this late in the season, though any snow is welcome news for farmers and the environment. Across the region, the snowpack has hovered at just 50 percent of normal.

“We’ll see improvement on that over the next two to three weeks,” said Joe Solomon with the National Weather Service in Pendleton. “The next three to four weeks will be critical for the amount of snowpack we get in the mountains.”

It’s also welcome news for Oregon ski resorts seeking a much-needed boost. Mount Bachelor received an inch of new snow in the past 24 hours, allowing staff to expand lift and terrain openings on the mountain.

“It really has inspired ski season once again,” said Drew Jackson, director of marketing and communications at Mount Bachelor. “Folks were a little down on the conditions before this weekend but now with the improved conditions, folks are much happier.”

This story will be updated. Amanda Peacher contributed to this report.