Turnagain Pass

In the upper elevations, above 2500’, where drier snow exists Easterly winds 20-30mph will be actively transporting snow. In the afternoon up to 5” of new snow is possible and newly forming slabs could grow up to 12” thick on leeward features. It’s also possible that someone could trigger an older storm slab due to a slick bed surface that was buried earlier in the week. On Thursday several small human triggered avalanches were reported on Eddies and in Main Bowl on Seattle Ridge following a storm that ended Thursday morning. These slabs were pretty shallow 6-10” and the bed surface was an old melt/freeze crust. Spring time warming and sun also contributed to instability that day. Today it will be important to monitor how much new snow falls and how much snow is being transported by the wind. Shooting cracks will a clue that this new snow is tender. In Portage Valley where precipitation will be heavier natural storm slab avalanches will be possible. 

This small pocket on a W aspect of Eddies was triggered by the first skier. The third skier also triggered a small pocket adjacent to this avalanche. See photo below. 

A slick melt freeze crust was present prior to the storm that ended Thursday morning and one of the skiers involved reported feeling the crust bed surface.

Triggering a wet avalanche will be possible below 2500’ today where rain and wet snow will be falling. Overcast skies, light rain and above freezing temperatures have kept the snowpack wet in the mid and lower elevation bands all week. Today scattered rain showers and up to 0.3” rain/snow water equivalent is possible by this afternoon with an additional 0.5” of rain by late evening. Coastal areas will see higher amounts. Evaluate the snowpack for wet, soupy and non-cohesive snow. In places where rain is falling, avoid steep terrain if your skis or snow machine start to trench into the snow. In the mid elevations where wet snow is falling on a slick crust, wet loose avalanches will be proportional to how much snow falls today. If you’re out later into the evening wet loose avalanches could become unmanageable in a terrain trap or on a larger slope. 

In Portage Valley where precipitation will  be heavier today, be aware of popular hiking areas with avalanche terrain above like Byron Glacier trail. Natural wet avalanches are possible in this area. The photo below was take yesterday of lower elevations of Maynard Mountain above Portage Lake.

Cornices are starting to fall. New snow and wind will be adding additional stress today and through the weekend. Give them plenty of space and limit exposure time underneath.