Active weather expected across the PNW Sunday

PORTLAND, Ore. (KOIN) — The Sunday Portland forecast calls for wet and breezy conditions at times with soaking rain possible throughout our early morning hours.

Daytime highs drop into the upper 40s along the Willamette Valley Sunday and to start the new week. Meanwhile, the Oregon Coast and the valley could see some active weather Sunday afternoon with a slight chance of isolated thunderstorms.

Rain accumulation in Portland is expected to be about a half-inch on Sunday. That will likely push Portland more than an inch above the average December rainfall amounts -- and more heavy snow is on the way from Sunday morning to Monday morning.

Snow elevations will be right around 3,500 feet to 4,000 feet through Monday. Another foot of mountain snow is possible for Oregon's ski resorts by the start of the week.

Weather Alerts

The National Weather Service has issued a Winter Storm Warning for the South Washington Cascades and the Northern and Central Oregon Cascades that is in effect from 1 a.m. Sunday to 4 a.m. Monday morning above 3.500 feet.  Mountain passes could see 10-13 inches of new snow accumulation.

There is also a Winter Weather Advisory for the South-Central Oregon Cascades all day Sunday from 4 a.m. to 10 p.m.

Looking ahead to Tuesday and Wednesday mornings, we'll see chilly morning with the overnight lows dropping into the upper 30s around the Portland metro area and much of the Willamette Valley.

So have the flannel and rain gear handy as we wrap up 2024.

Stay with the KOIN 6 Weather Team for the latest on the forecast across the Pacific Northwest.