Turnagain Pass

There were no new avalanches reported yesterday. This was the first day in two weeks that we did not hear about natural avalanche activity. However, temperatures did get into the 60°Fs yesterday an we have another hot sunny day on tap today. As noted above expect the avalanche danger to rise as the snow heats up.

Timing and aspect choices are the keys to having a safe and fun day in the mountains this time of year. Instead of thinking about winter avalanche concerns the heat and direct sun are saying —All right! Stop whatcha doin’ Cause I am about to ruin the powder and the riding that ya used to! (RIP Shock G) —it’s time to monitor crusts, snowpack saturation and understand which aspects are heating up first.

After a night of clear skies and radiant cooling creating a surface crust, temperatures are forecast be in the 50°Fs and 60°Fs again today. If you are venturing out to play in the sun, paying attention to surface conditions and overhead hazard will be crucial. Once crusts soften a little riding can be quite fun. However, triggering a wet loose avalanche will be likely on steep slopes with boot-top (or deeper) wet surface snow. If you are sinking in on your skis or trenching on your snowmachine or punching through with your boots it’s a good idea to get off the slope. Triggering roller balls or small push-a-lanches where the surface snow picks up momentum and entrains more surface snow are a good indicators of increasing hazard. Even a small wet loose avalanche can be dangerous if you get caught and they have the potential to gouge down taking the entire snowpack, becoming large and destructive. In addition, it will be possible to trigger a wet slab on slopes seeing significant warming.  Wet slabs avalanches happen when a weak layer or interface becomes moist or wet. The wet snow loses strength and the snow above fails and avalanches. Wet slabs are often triggered by a wet loose avalanche and are most likely to occur in areas with a thinner snowpack, such as Summit Lake.

As you plan your day think about what slopes are heating up. In addition to human triggered avalanches being likely when the surface snow loose strength, natural wet loose and wet slab avalanches will be possible today. Remember north and east aspects warm first, then south, then west, and last north gets the sun again this time of year.  Steep rocky terrain warms up quickly! Natural roller balls are a sign slopes are heating up. Exit routes require thought as well this time of year. Be careful not to traveling across or under suspect slopes on the way back to the car.

Cornices: Warm temperatures and direct sunshine can destabilize this looming hazard. Cornices will become easier and easier to trigger as time goes on. A cornice fall could trigger a wet avalanche on the slope below. Be aware to not accidentally travel onto one and limit any exposure under them.

Crust or no crust? That is the question today. Surface crust on Cornbiscuit yesterday, 4.24.21. Photo: Heather Johnson.

A cornice fall today could trigger another large wet loose avalanche on the west face of Pyramid, photo yesterday 4.24.21. 

There have been some large glide avalanches over the last 10 days and there are glide cracks littered across the forecast area. Remember glide cracks can release at anytime. Avoid/limit spending time underneath them. Don’t mess with the brown frown!

Glide avalanches and glide cracks near the Seattle Ridge uptrack, 4.24.21.

Cornbiscuit glide avalanche and cracks, 4.24.21.