Weather Synopsis for Saturday night through Monday

A significant winter storm is bearing down on the Pacific Northwest Saturday afternoon bringing strong winds, heavy precipitation, and fluctuating snow levels. Radar returns show the leading edge of the precipitation reaching into the Cascades this afternoon (Saturday 2pm). Currently, most NWAC weather stations report below-freezing temperatures. Expect precipitation to start as snow in most locations. However, this evening, a sharp warm front will send temperatures climbing and cause a change from snow to rain at most trailhead and pass elevations. Snow levels should peak sometime in the early morning hours between 5000 and 7000ft. In addition to the warming temperatures, expect periods of intense precipitation with significant spillover to areas east of the Cascade Crest. Winds will also increase, becoming strong and gusty in most locations. Wrap all this together and it's going to be a very stormy night in the mountains. 

With the jet stream trained on Washington, the stormy weather will continue Sunday. A trailing cold front should push through the region in the morning and deliver yet another round of heavier precipitation and gusty winds. As it exists, snow levels will slowly drop. The passes should transition back to snow sometime in the mid-afternoon. As the jet stream slowly drifts southward, expect the heaviest precipitation to focus on Mt Hood, Mt St Helens, Mt Adams, and Mt Rainier. 

Sunday night and into Monday, onshore flow and a steady stream of moisture should keep significant snow showers in the mountains. A Puget Sounds Convergence Zone should provide locally heavier precipitation to the central Cascades. Right now, this feature seems to focus on the Mountain Loop area, but a subtle shift could bring more significant precipitation to Stevens Pass. Snow showers and ridgeline winds should finally ease Monday afternoon, but only after a wet, wild, and windy 48hrs in the mountains.