Wind chills of 20 to 25 degrees below zero are in the forecast for the Tri-Cities, Prosser, Connell and Sunnyside from Friday night to Saturday morning, the National Weather Service reports.
The wind chill watch is in effect from 10 p.m. Friday to 10 a.m. Saturday.
Northerly winds with arctic air mass will create dangerous wind chills and the cold weather will last into early next week, the weather service says.
A surge of arctic air will push in from Canada bringing much colder temperatures and northerly winds starting Friday evening through Sunday morning.
Wind chill values may potentially drop to dangerous levels.
Those who must be outside should dress in adequate clothing and minimize exposure, the weather service says. Pets and livestock also are affected by the cold. Ensure pets and livestock have a warm dry shelter. And access to food and fresh unfrozen water, the weather service says.
A wind chill watch means that there is the potential for a combination of very cold air and strong winds to create dangerously low wind chill values, the weather service says. Frost bite can occur in less than 30 minutes. And hypothermia may occur if precautions are not taken.
A hazardous weather outlook also has been issued for the Yakima Valley, Lower Columbia Basin, Blue Mountains and east slopes of the Cascades.
A low pressure system approaching the region will bring a chance of snow later tonight, the weather service says.
The low will move through Friday and Saturday with snow. Several inches of accumulation are likely over central and northeast Oregon.