Snow covers Roderick Road near Gales Creek on February 10, 2019. Photo: Chas Hundley

The Portland branch of the National Weather Service issued a Winter Storm Watch for most of northwestern Oregon and southwest Washington on Wednesday, warning of weather conditions starting Thursday and extending through Saturday that could bring rain, snow, freezing rain, wind, and plunging temperatures.

Thursday afternoon through Friday morning are expected to see the worst of it, the weather agency said, with a possibility of up to five inches of snow and up to one-tenth of an inch of freezing rain possible in the Timber area, while areas in and around Banks could see two to six inches of snow mixed with rain, freezing rain and wind gusts.

The Thursday afternoon and Friday morning commutes are likely to be impacted, the NWS said.

"Travel could be challenging at times," the agency said, noting that "the coastal mountain valleys may experience significant amounts of ice accumulation during this time, but confidence is low."

The NWS is predicting lows of around 26 degrees Fahrenheit on Thursday night, and around 21 on Friday night.

Washington County posted a social media message warning that wind gusts and ice in the forecast could cause power failures, and listed several ways to be prepared.

Another winter storm could be moving into the region starting Sunday night through Monday morning, but forecasters were not yet certain what it might mean for the region.

The Oregon Department of Transportation offered this advice for motorists in advance of the expected winter storm:

The safest speed is often below the posted speed limit.

Expect delays, plan ahead, allow extra travel time and know before you go.

Watch the forecast along your route both for the trip out and the trip home. Conditions change as storms come through.

Bicyclists should remember that vehicles can’t stop quickly on snow or ice and motorists need to remember than bicycles are more difficult to see in low visibility,

Drive to conditions. Slow down. Be ready for road conditions to change from wet to snow to ice and watch for debris on the road.

Use caution going over mountain passes. Check the TripCheck.com for closures and go to the cameras for conditions on your route. Many camera displays include temperature, elevation and other helpful information. A blue dot will tell you the road conditions along with traction and chain requirements.

Carry chains and know how to use them. Put them on when directed or when you need them.

Pay attention to the roadside variable message signs. They contain critical information about real-time conditions, including crash and detour instructions.

Pack supplies for you and your passengers in case of major delays. Include food, water, blankets, warm clothes and medications. Keep your cell phone charged. Don’t forget your pets. They have needs too.

Perhaps most important, make sure there’s a sober, focused and alert driver behind the wheel to help you arrive safely, wherever you may go. Buzzed drivers are drunk drivers.