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.

An ice storm warning has been issued for the southern and central Willamette Valley for freezing rain and snow likely to disrupt work, school and travel on Thursday and Friday. Power outages also appear increasingly likely. The warning is in place from 10 p.m. Wednesday to 4 a.m. Friday.