Snow forecast Willamette Valley: Several inches possible Wednesday

Chances are improving for snow in the Willamette Valley on Wednesday afternoon, even after they seemed to diminish on Tuesday morning.

There is now “moderate confidence for several inches of accumulating snow with travel impacts” somewhere in the Willamette Valley, including Portland, according to the National Weather Service in Portland.

“Overall, across the I-5 corridor as a whole, over our forecast area, there’s a 45 to 60% chance of one to two inches or more of snowfall occurring somewhere in that area,” said David Bishop, a meteorologist with the National Weather Service in Portland on Tuesday afternoon.

What remains uncertain is where the low-pressure band will set up and drop snow.

There is a 40 to 65% chance that measurable snow will fall somewhere along I-5 starting Wednesday and through noon on Thursday, with the most likely scenario bringing snow to the central coast, the central and northern Willamette Valley, the Columbia River Gorge and the Portland and Vancouver areas.

But still, even though the possibilities have narrowed, the National Weather Service does not have a lot of certainty exactly where the system will land.

“This is honestly one of the issues that we’ve been having with this system,” Bishop said. “The models are not in good agreement at all as to the path that the low will take and that’s what is the linchpin in determining where the snow band will potentially set up.”

Track 1, which has the snow accumulating further north, and Track 3, which has the snow landing further south, both have about a 20% chance of happening, Bishop said.

Track 2, which is the most likely scenario, has around a 40% chance of happening.

And then the remaining 20%? That has the system setting up “anywhere from the Olympic Peninsula down into California,” Bishop said.

The upshot is that as of Tuesday afternoon, snow wreaking havoc during the Wednesday evening commute is still a possibility, somewhere along I-5.

No matter what happens on Wednesday, however, snow and ice aren’t expected to stick around for long. The high Thursday in Portland is 45 degrees.