GRESHAM, Ore. -- Black ice surprised some drivers early Thursday morning in the Portland Metro area.
There were at least six crashes reported that were blamed on black ice, including a car that crashed into a tree near Southeast Foster Road and 172nd Avenue, just south of Gresham, and a head-on collision near Northwest 185th Avenue and Walker Road in Hillsboro.
"If you have to scrape your windshield, there might be black ice on the road," warned Lt. Steve Alexander of the Multnomah County Sheriff's Office. "You just need to be careful."
In Molalla, a car collided with a school bus in a crash that was also due to icy conditions. No children were on the bus. The driver of the car was flown to a local hospital in a LifeFlight helicopter with serious injuries, authorities said. The bus driver was treated for minor injuries and released.
The cold weather will be back Friday morning, KGW Meteorologist Nick Allard said, but the moisture shouldn't be a problem.
"We'll start even cooler, with temperatures in the lower 30s and areas of fog. Into the afternoon we may see a few showers in the mountains but that should be it," he said.
More: KGW weather forecast