Portland-area residents should be prepared for a marked change to much colder weather across the region this week, with the potential for temperatures dropping into the teens, followed by snow and ice, according to meteorologist Steve Pierce.
A very cold system originating in the Arctic will sweep across the region Tuesday, Pierce said in a news release on Sunday. In the wake of this, temperatures will fall during the day with cold easterly wind developing, especially near the Portland metro area and the Columbia River Gorge.
Even colder air is likely to invade the area on Wednesday, said Pierce, owner of Northwest Weather Consultants.
Once this second shot of cold air is in place, daytime high temperatures will struggle to get above freezing up and down the I-5 corridor. Overnight low temperatures will drop into the teens at many western valley locations.
This would be the second such arctic event of the season, which is rare by Pacific Northwest standards, Pierce said. This type of pattern is also rare for February and only a few have occurred in the past 25 years most notably in February 1989 and February 1996.
The last arctic event occurred in early December and set overnight low temperature records at many locations across the Pacific Northwest.
Next weekend, Pierce said, a warmer and wetter system will approach the area from the Pacific Ocean. As warmer moist air from the Pacific overrides the cold air trapped at the surface, snow will likely be the result at first, followed by a transition to freezing rain as the cold air above is eroded away.
Pierce said areas near Portland and the Columbia River Gorge will be the last to transition out of the cold air. Exact details of next weekend's potential snow and freezing rain have yet to come into focus through computer models, Pierce said.