Mountain Weather Forecast

Weather Synopsis

The wet and wild weather will continue as we head into the holiday weekend. The first in a series of atmospheric rivers will continue to spread rain and high elevation snow from north to south across western Washington Thanksgiving night. The heaviest precipitation is expected around the Cascade Volcanoes and in a Puget Sound Convergence Zone which should take aim at areas from the Mountain Loop Highway to Snoqualmie Pass. Snow levels with this first storm will remain well above trailhead and pass levels. The notable exception is lingering pockets of colder air holding strong near the Canadian border, particularly in the Methow region. In addition to the warm temperatures and heavy precipitation, strong westerly winds in most areas will make for very storm conditions. 

As we head into Friday, slightly cooler weather will begin to shift into the region. As it does so, most of the precipitation ends. Notable rain and snow should continue for locations near Mt Hood and where the convergence zone remains focussed. By mid-late afternoon, a brief break in the action should allow most locations to dry out as shower activity comes to an end. A few sun breaks could even be possible for areas east of the Cascade crest. 

This break appears short-lived. A second, and slightly stronger, atmospheric river will begin to approach the region Saturday morning. Weather models disagree slightly with the timing of this system but generally agree on the major impacts and pattern. Moderate to heavy precipitation and strong winds will spread from NW to SE across the area Saturday afternoon. Locations in the Olympics and N. Cascades will see the most significant accumulations during the day, but as the storm continues, precipitation will spread further south. Very warm air should arrive with the onset of precipitation and send snow levels soaring. Right now, this appears to be yet another mostly rain and very high elevation snow event for the mountains.