A powerful cold front has stalled out over northwest Oregon, but it will sag southward very slowly tonight as it moves through the state.
With this frontal boundary, expect spells of moderate to heavy rain tonight and tomorrow, with snow expected at altitudes over 500 to 1000 feet in the mountains.
Snow levels in the Columbia River Gorge and the Upper Hood River Valley may decline late Sunday or early Monday.
The unpredictability of the weather will continue for the remainder of the week, with snow levels dropping again later in the week.
Increasing amounts of snow have been falling in the northern regions of the forecast area, particularly in the Greater Portland-Vancouver urban areas and the Columbia River Gorge, which includes the Hood River Valley.
As a result of the cold front stalling over the region, more accumulations are likely.
Even though temperatures hang just above freezing, the increased rainfall has been sufficient to chill the atmosphere, resulting in snow formation adiabatically.
The amount of snow accumulated ranges from a trace in the northern Willamette Valley in the Oregon City, OR region to around 2 inches in the higher altitudes of the Camas, WA area, and everything in between.
According to reports from the public, the regions near Corbett and Boring have had some of the largest accumulations of snow so far this winter season. Because of the slight fluctuations in intensity and temperature, the accumulations have been patchy and varied.
Several reports have classified most of the precipitation as wet snow.
At this moment, the Cascade Foothills and the Hood River Valley are the areas that are most concerned about snow accumulation.
As temperatures continue to drop overnight, snow will most certainly begin to pile on highways, potentially resulting in hazardous driving conditions.