Winter Weather Advisory Through Wednesday Night: Up to 6 Inches of Snow in 2 States

Up to 6 inches of snow is forecast for the high passes under winter weather advisories from the National Weather Service, with snow showers continuing through the evening before tapering off overnight. The advisories cover elevations above 4,500 feet, with the largest totals above 6,000 feet, and Oregon’s rules on chains and traction tires apply on the passes inside them.

Snow Totals For The Cascades

The NWS Portland winter weather advisory splits the range in two. In the North Oregon Cascades and the South Washington Cascades, it runs until 2 a.m. ET Thursday and calls for 1 to 3 inches above 4,500 feet, with 3 to 6 inches above 6,000 feet. Government Camp, Bennett Pass, Timothy Lake, Lost Lake, Larch Mountain, Mount St. Helens and the Indian Heaven Wilderness fall inside it.

Farther south, the Cascades of Marion, Linn and Lane counties are under a shorter advisory that ends at 8 p.m. ET Wednesday. Forecasters expect a trace to 3 inches above 4,500 feet, with the most in the Marion and Linn County Cascades, covering Santiam Pass, Santiam Junction, McKenzie Pass, Willamette Pass, Tombstone Summit, Breitenbush Springs and Waldo Lake. In both zones, Portland warns that roads, and especially bridges and overpasses, will likely become slick and hazardous.

How Oregon Chain Rules Work For Passenger Cars

Oregon posts its requirements on signs at the snow zones, and the wording matters. According to the Oregon Department of Transportation, a “Carry chains or traction tires” sign means the equipment has to be in the vehicle, while “Chains required, traction tires allowed on vehicles under 10,000 GVW” means passenger cars can keep going on traction tires instead of chains, as long as they are not towing. When chains do go on a car or light truck, ODOT requires them on one tire on each side of the primary drive axle.

Ignoring a sign that only requires carrying the equipment is a Class C traffic violation. Failing to use chains or traction tires when the sign requires them can bring a specific fine of $800.

What Counts As A Traction Tire

A tire qualifies when it carries the three-peaked mountain and snowflake symbol on the sidewall, and studded tires count as well. Studs stay illegal in Oregon until Nov. 1, though, so for this storm the tire has to earn the rating without them.

Where AWD And 4WD Fit In

All-wheel-drive and four-wheel-drive vehicles get an exemption from chain requirements in most winter conditions, but ODOT attaches a list of conditions. The vehicle must power both axles, weigh no more than 6,500 pounds unloaded, wear mud and snow, all-weather radial or traction tires on all four wheels, avoid towing, and still carry chains. A crossover on summer tires with no chains in the cargo area does not meet the exemption.

During a conditional road closure, ODOT can extend chain requirements to AWD and 4WD vehicles as well, depending on the conditions. Portland’s advisories send drivers to TripCheck or 511 for current Oregon road conditions and chain restrictions, and to the WSDOT real-time map for the Washington side of the zone.

About the author

Co-Editor-in-Chief, Autoblog

Adam Lynton is Co-Editor-in-Chief at Autoblog with over 15 years of automotive journalism experience. A member of the Automotive Press Association and International Motor Press Association, Adam specializes in vehicle reviews and industry analysis, blending deep car culture roots with a global editorial perspective.