The models have been hinting at a possible Atmospheric River event next week for the Pacific Northwest with several periods of significant rain and high mountain snow.  Several feet of wet snow is possible over the higher summits of Whistler through the period beginning Monday. Heavy snow will be falling over the Oregon Cascades today through Friday.

The challenge will be snow levels as warm fronts with significant moisture are followed by colder air so amounts will be very variable depending on timing and elevations next week.  Canada will reap initial rewards with cooler temps however the Cascades of Washington and Oregon will eventually do well perhaps later next week? Several periods of heavy rain followed by snowfall are possible next week for the Cascades. Snow amounts will very variable depending on elevations. An AR event technically needs tropical moisture that is still possible however it's not a slam dunk. Regardless, it's going to get progressively wetter especially mid to late next week! Whistler may end up a winner by this time next week at the summit. 

Below: Long term ensembles showing deep low pressure over the Pacific Northwest mid next week. Moisture increases in the long term ensembles beyond that. 

In the short term, we are watching a weak system today followed by a moderate system Thursday for the Cascades of WA/OR and some of the first flakes for the Idaho Panhandle (Schweitzer).  Cold air will bring some snow to the bases of most ski areas of the Northwest this week.  Most areas will see 2-5 inches at upper elevations before heavy snow takes hold over central Oregon. "A good portion of the Oregon Cascades will see a foot or more through Friday".  That might include Timberline Lodge (Open), and perhaps Bachelor where several inches of snow are likely especially late tonight through Friday morning. "I was up at Bachelor snowboarding (Closed) several weeks ago when they nabbed 20 inches (Early season bonus)."

Below:  Total snowfall for the Northwest including the Panhandle through Saturday night. Highest amounts will be in the central Oregon Cascades and the summit of Mount Rainier through Friday.

The long term ensembles are showing significant moisture for the Northwest late next week (Rain and snow) with flip flopping snow levels.  There are cold fronts that could bring impressive snow totals to certain areas.  Since it's 7-10 days out I have marginal confidence at this point with the rain/snow lines.  Those systems most likely we take a northerly route before diminishing as they move over the northern Rockies.  It's possible that some resorts in the Pacific Northwest log deep snow up top and significant rain at the bases (its only early October). 

Please follow "The Chase forecast" updated as conditions change.  

Forecaster: Powderchaser Steve