After the first round of a powerful snowstorm that plastered western Oregon and southwest Washington with up to a foot of snow, forecasters say get ready for more.
A winter storm warning was issued for a large swath of the state early Friday, with snow expected to begin in the central Willamette Valley in early afternoon before moving north into northwest Oregon and Portland by late afternoon. The warning remains in effect until 10 a.m. Saturday morning.
As with Thursday’s storm, cities south of Portland--Albany, Corvallis and Philomath--could see another half a foot of snow to add to the 10-12 inches already on the ground.
The warning also extends into the north and central Oregon coast and the Oregon coast range, which also saw anywhere from 8 inches at Manzanita, to 13 inches in Vernonia.
Portland, too, will get into the action with another 2 to 6 inches of snow forecast to fall on the official tally of 3.5 inches measured at Portland International Airport. The National Weather Service has compiled an extensive list of snowfall totals and posted them online.
“Friday’s system is looking eerily similar in timing and expected snowfall to Thursday’s system,’’ said Jeremiah Pyle, a forecaster for the National Weather Service in Portland. “The only difference is we’re seeing more of a threat from a wintry mix of sleet and freezing rain to our south.”
As with Thursday’s system, snow and/or freezing rain is expected to begin falling on the Oregon coast my late morning, before the system, moves ashore and into the Central Willamette Valley by early afternoon.
Places such as Eugene could see the precipitation start as snow before switching over to sleet or freezing rain. But with cold air trapped in the valley, Pyle said, it’s going to be good for sledding and bad for travel.
The precipitation will then move north into Portland and Vancouver by late-afternoon or a few hours later than with Thursday’s system and falling exclusively as snow.
Models do show that the system appears to be packing more moisture than Thursday’s, which could ramp up snowfall amounts. Pyle said warm Pacific air and cold air spilling west out of the Columbia River Gorge will create what forecasters are calling a squeeze play. These two forces will combine to create lift and enhance precipitation.
But the warmer Pacific air is going to make a steady march to the north. Friday morning, Eugene hovered at around 20 degrees while 72 miles south in Roseburg the temperature was relatively balmy 40 degrees.
By late Saturday into Sunday, Pyle said the weakest of the 3 weather systems will bring another round of rain, sleet, freezing rain and snow to the region.
“This system will have the lowest impact in terms of snowfall, but the threat of freezing rain on top of snow could make it the worst day for travel,’’ Pyle said.
By late Sunday, he said, precipitation will turn to rain for most of western Oregon, with a steady march of rainy weather systems for lower elevations, and much-needed boost to snowpack in the Cascades.