Turnagain Pass

Yesterday afternoon Easterly ridgetop winds suddenly increased into the 20’s mph with gusts in the 40’s mph creating 6” tender wind slabs. A small natural avalanche was observed on a Northwest aspect on Superbowl, near Corn Bicuit, and shortly after a skier triggered a wind slab on a steep convexity at 2300’ in this zone. Overnight another 6” of snow fell and strong Easterly winds continued. Today winds and precipitation are expected to decrease, before another burst of wind and snow arrive late this afternoon/early evening.

Today wind slabs 8”-20” will be easily triggered on wind loaded terrain features such as below ridgetops and on convex rollovers. These slabs will be more developed on Western aspects (Southwestern – Western – Northwestern.) Areas such as the Western facing bowls of Seattle Ridge will be suspect in the mid elevation band (below 2500’.) Pay attention for cross-loading on all other aspects.

Managing this hazard will be possible by choosing low angle terrain and sticking to routes that are scoured and wind eroded. Be on the lookout for denser snow on top of weaker snow below; shooting cracks will be an instant sign that this snow is tender. Both hard and soft wind slabs could be present today, and both have the potential to fracture above you. Luckily this is a surface instability issue, meaning these slabs will be isolated to wind loaded zones, and triggering an older deeper layer below is unlikely. However that being said these slabs are expected to be touchy and even a small isolated slab in the wrong place can have high consequences. 

Debris from a skier triggered slab on Superbowl, Northwest aspect, near Corn Biscuit yesterday afternoon. This fresh wind slab was 6″ deep, 40′ wide and ran approximately 150′. 

Alaska Avalanche School Level 2 class dug a pit in an area where they observed a 20′ shooting crack near Common bowl on Tincan. Click HERE for observation. 

Glides continue to slowly open and every once in a while one will release. There is no discernable pattern to predict their failure as they tend to fail naturally and on their own schedule. Warm temperatures can trigger them and so can cooling temperatures. A new glide avalanche was seen on East Seattle Ridge yesterday at (~1300) and one released on Sharks Fin (South facing ~2,000′) mid week. Since glide cracks can spontaneously release at any time, it is best to avoid, or do your best to limit time under them. With questionable visibility again today, it may be difficult to identify glide cracks. 

Small glide release seen yesterday along Seattle Ridge at ~1300′. Timing of release is unknown. Many large glide cracks can still be seen all along Seattle Ridge East face.