If temperatures drop below freezing, she said, it could lead to “major ice build-up,” creating hazardous driving conditions. Melting snow and ice in some areas are also leading to high water and standing water hazards, she said. If temperatures fall, these could also re-freeze.

Much of the Willamette Valley turned white on Thursday morning as a few inches of snow fell from Eugene to Portland. Here's how much snow fell.

Snow and freezing rain is likely to continue impacting roads and schools until a widespread warmup midday Friday across the Willamette Valley.