Turnagain Pass

For the third night in a row temperatures stayed above freezing in the low to mid elevations and over 1.5″ of rain fell on the snowpack in the last 24 hrs up to 2000′ or higher at Turnagain Pass. Natural wet loose avalanches were observed yesterday and were large enough to injure or bury a person. Triggering a wet loose or a wet slab avalanche in this saturated snow will be likely today and may be occurring naturally as well. Wet avalanches once initiated can entrain more snow rapidly and are very hard to get out of. They can be particularly hazardous if they push you into a terrain trap and bury you deeply. Stick to low angle terrain and avoid runout zones where avalanches from above may catch you. Warm temperatures and rain showers are forecasted to continue today. There may also be some sunshine that could exacerbate the wet snow issues. Ski and snowmachine conditions will not be pleasant.

Turnagain Pass weather at 2:30 pm yesterday.

We have been talking about glide cracks and glide avalanches for months and the past couple weeks have been notably active. The past couple days maybe even more so as the snowpack gets wetter and more slurpy like. New cracks are appearing and releasing as very large glide avalanches. The idea of someone getting caught in one of these is pretty terrifying. Navigating through the mid-elevation band is getting more and more complex. There is a glide crack that is opening directly above the Seattle Ridge up-track. I couldn’t get a good picture of it yesterday but I don’t want to be parked or stuck under that and traveling under a glide crack is a total dice roll. The only way to mange this hazard is avoidance. 

Glide avalanche above the Bertha Creek parking lot.

 Debris pile from the avalanche above.

 Whiteline avalanche path glide crack to glide avalanche progression over 3 days. Images from 3.20, 3.21 and 3.22. Photos: Tim Glassett

Wind slabs and Cornices:

Yesterday in the Alpine the precipitation was falling as snow and there were sustained easterly winds in the 20-30s with gusts into the 50s. This may have created tender wind slabs in ridgeline starting zones and added weight to already very large cornices. The wind slabs will be found in steep leeward terrain. Watch for cracking in wind-loaded areas and avoid travel on or under cornices. Warm temperatures can make cornices more likely to fail.