Lingering showers will taper early tonight, as cooler air moves into the Willamette Valley and Umpqua Basin. Snow levels will drop to near 500 to 2000 feet, though significant lowland snow is not anticipated despite cooler temperatures. Later into Monday, surface high pressure will begin to build inland, leading to dry and seasonably mild conditions.
Attention then turns to a robust system arriving midweek, originating from the Gulf of Alaska. This system is expected to bring widespread rain west of the Cascades and significant snowfall to the Cascade Range. Heavy precipitation, possibly exceeding an inch Wednesday through early Friday, is likely across the region, especially along the Coast Range…