PORTLAND, Ore. - Wet roads froze and perhaps some freezing rain was thrown in for good measure Monday night and will make driving conditions tricky in some areas Tuesday morning, but will mostly be a problem at higher elevations.
The Oregon Department of Transportation is warning drivers to be extra cautious while driving Monday night and Tuesday morning after minor precipitation left the roads wet and didn't evaporate in time for the nighttime freezing temperatures.
Icy roads Monday night caused emergency crews to shut down Miller Road in Northwest Portland. The ice turned the road into a wild and dangerous ride in just a matter of minutes.
Six cars and one small bus were involved in wrecks on the road. A car launched into a parking lot, the bus hit a concrete wall and a Prius got wedged under a power pole.
In many areas early Monday evening, temperatures dropped below freezing, but by the end of the day they had gone up a couple degrees and were hovering at or just above freezing.
KATU Meteorologist Dave Salesky said precipitation lessened later in the night and was mostly on the east side of the county. He said the slick road conditions expected for Tuesday morning will mainly be in the higher elevations.
"Most areas, though, should escape a lot of the ice for (Tuesday) morning's commute," he said.
The area was experiencing an "inversion," in which warmer air trapped colder air beneath it.
"The coldest air is down at the very bottom of the atmosphere, near the surface," Salesky said. "As a matter of fact, the daytime high today at Timberline Lodge was 44 degrees" while Portland only reached 33 degrees.
ODOT crews will be out overnight applying deicer to roads to help keep them in relatively good condition.
Drivers are encouraged to drive slowly, allow three times the normal stopping distance and watch for ice, especially on bridges and overpasses.
Commuters can check their driving routes by going to TripCheck.com.
A Freezing Rain Advisory was in effect until midnight Monday.
Watch the latest forecast: