The weather pattern remains consistent with the past several days, dry and quiet. An air stagnation advisory is in effect through Saturday at noon due to the strong inversions building in the overnight hours and the lack of mixing.
Beginning Sunday, an arctic air mass will begin to push into the Northwest from the Gulf of Alaska. This will bring a quick drop in snow levels for early next week. The computer models the past several days have been pretty inconsistent with the timing of this system’s arrival but it seems as though showers in Southern Oregon will not begin until late Sunday, and this will be mainly for areas west of the Cascades.
At the Coast, showers will begin earlier on Sunday – probably in the afternoon. Many locations, especially the higher elevations, will be making a change over from rain to snow on Monday with widespread shower activity and lowering snow levels.
I suspect by late afternoon and early evening, the passes will begin seeing impacts from the winter weather. By Tuesday morning, snow levels will be down to the Valley floor. Showers will begin winding down at this point, but isolated showers will likely bring snowflakes to the Rogue Valley.
Those traveling back into Southern Oregon from Portland or Seattle on Sunday should keep a very close eye on the forecast. The arrival of the cold air and lowering snow levels will be much sooner the further north you are. They should stay between 6,000’ and 7,000’ Sunday across Southern Oregon.
Meteorologist Alyssa Caroprese