"Portland Braces for Ice Storm: Traffic, Power Outages Expected"

Portland is experiencing freezing rain instead of snow due to a warmer system causing the air aloft to be warmer than the ground. The precipitation starts as snow but melts as it falls through the warmer layer, then refreezes as it hits the cold air closer to the surface, creating freezing rain. Temperatures are expected to climb above 32 degrees on Wednesday, shifting the precipitation to rain, but slick conditions will persist.