Turnagain Pass

There were several human triggered avalanches yesterday. Two people were caught and carried in two of these with one injury. All these avalanches are suspected to have failed on the layer of buried surface hoar that formed on March 16th.
*We thank all these individuals for taking the time to write in.

Seattle Ridge, Zero Bowl/Hidden Bowl: A skier triggered a 12″ deep and very wide propagating slab avalanche (WNW, 2,800′). This slab caught and carried the skier. The skier was not buried, but did sustain a knee injury. See the report HERE.

Goat Mtn (near Super Couloir):  A snowboarder was caught and carried roughly 1,000′ in a slab avalanche in steep terrain off Goat Mtn (S, 4,800′). The slab was estimated at 8″ deep, 300′ wide and running 1,500′. The rider was not buried and uninjured. Report HERE.

Seattle Ridge, Main Bowl:  Three avalanches reported. One was a skier triggered slab on the looker’s left side of Widowmaker slide path (SW, 2500′). Skier was able to ski off slab. The other two were snowmachine triggered on the shaded westerly side of the bowl, just off Seattle Ridge itself, no one known to have been caught. Report HERE.

Placer Valley:  Snowmachine triggered slab around 18″ deep, 100′ wide, running 150′ (W, 2,500′). No one caught. Report HERE.

Hidden Bowl (Zero Bowl) in the Seattle Ck drainage. Skier triggered by first person on slope, skier sustained knee injury. Photo by Nick Langowski, 3.20.22.

Goat Mtn slab that was triggered by a snowboarder. Rider was carried around 1,000′ and thankfully was uninjured and not buried. Anonymous photo 3.20.22.

Widowmaker slab (looker’s left side). Skier was able to ski off slab and was not caught. Anonymous photo 3.20.22.

With one more day of quiet and sunny weather bringing in the ‘spring’ season, we can expect very similar avalanche conditions today that we had over the weekend – the possibility of triggering a slab up to 2′ deep. The layer of surface hoar that was buried on March 16th is a problem, as proof by the many recent human triggered avalanches. That said, today our hackles should still be up.

Most of these slabs have been on shaded aspects, mainly because that’s the best snow to ski/ride, and there are not sun crusts tying the slope together. However, southerlies in the heat of the day, when the crusts soften, are suspect for triggering a slab as well. The 3/16 buried surface hoar sits roughly 12″ deep at Turnagain Pass and 18+” deep in Placer Valley and Girdwood. We have seen some of these avalanches propagate very wide, especially the slab triggered in Zero Bowl on the backside of Seattle Ridge. Another photo of that avalanche is below and more can be seen in the report linked above.

Very wide propagation in the Zero Bowl avalanche. Photo by Nick Langowski, 3.20.22.

For folks squeaking out one more sunny day before the weather heads back in, not only is it very important to watch for all the regular red flags (recent avalanches?, shooting cracks?, collapsing/whumpfing in the snowpack?), but knowing there is a weak layer under your feet is key. Digging a quick pit to see if you can find the layer is great, but remember it’s hard to see and doesn’t always give us the right clues. We know it is in many areas, it just may (or may not) be very easy to trigger. We need to be sure to keep with safe travel protocol (expose only one person at a time, have an escape route planned, watch your partners closely). Remember, this type of avalanche can break after several people have been on a slope and/or could be triggered remotely. One can always stick to slopes 30 degrees or less if choosing to avoid the issue all together.

To make matters more confusing there is an older layer of buried surface hoar (18″ – 30″ or so deep) from March 2nd. Although this layer has been showing signs of bonding and we have not seen it produce avalanches recently, we are still keeping track of it.

Red Flags to watch for – note the cracking just above the snowmachine track. 3.20.22.

Lingering Wind Slabs:  Gusty east winds on Saturday formed shallow wind slabs in the upper elevations. Watching for wind loaded slopes and cracking in the snow around you will help suss out any lingering slab. It is also good to keep in mind that even a small wind slab avalanche could step down to the buried surface hoar and create a larger slide.

Wet Loose Avalanches:  Another warm sunny afternoon could cause southerly aspects to melt enough that human triggered wet sluffs will be possible. Natural wet sluffs may occur as well.

Cornices:  It’s that time of year when warm days can cause cornices to slowly ooze over and become easier for us to break them off. They deserve an extra wide berth. There was near miss with a snowmachiner who triggered a cornice fall and traveled over 1,000′ with his machine. Thankfully, the rider was ok.

Glide Avalanches:  Glide cracks continue to slowly open across the region. Keep an eye out for these and always limit time, or avoid if possible, being under them. They can release into destructive avalanches at any time.

Glide crack slowly opening on the southerly face of Eddies. Photo by James Howery, 3.20.22.