Turnagain Pass Avalanche Forecast

It is another wet and windy storm day in the Girdwood and Turnagain Pass area. Light rain fell yesterday up to 2000’ and has intensified overnight. Rain will persist through the day today adding up to another .75” of water. That said, wet avalanches due to continued rain on snow will be the main concern below treeline.

We have seen very little natural avalanche activity since Friday’s heavy rain event and widespread avalanche cycle. However, there was one wet slab noted on the Southeast face of Seattle Ridge just below treeline (photo below). This avalanche is one of the smaller wet slabs we have seen lately but it does show that the pack is still adjusting to the rain on snow – this can also be seen in Fitz’s video HERE from Sunday. With today’s increase in precipitation we could see a few more natural wet slabs release.

Natural wet slab avalache likely occurring Sunday or very early Monday.  (1800′, SE facing, 12-18″ deep x ~150′ wide)

Above treeline our snowpack is getting deeper by the day. We have had up to 3’ of dense heavy snow fall since Thursday night. Yes, this is good news for the upper elevations in the long term, but for the moment it is creating a dangerous deep slab avalanche problem. The weak faceted snow near the base of the snowpack was overloaded by Friday’s rapid loading event and several large full-depth avalanches occurred. Some of these propagated across entire slopes and deposited deep debris piles. This natural activity has since settled down and stability tests show likelihood of triggering becoming harder and harder but if it does go a deep and destructive avalanche is likely. With the continued stormy weather, warm temperatures, and very little upper elevation information, the deep slab issue continues to deserve much respect.

In short – this is a highly unpredictable but highly consequential avalanche problem.

In the upper elevations (above 2,500’) where it has been and will continue to snow, storm snow instabilities will be a concern. These are mainly in the form of wind slabs near the upper elevation ridgelines. The Easterly winds have been strong for over 24-hours on the ridgetops. Though wind slabs were abundant yesterday around 3,000’ they were shallow (6-8″ thick), stubborn and hard to crack. However, the higher one goes in elevation the more sensitive, and larger, they should be.

Cornice growth
Cornices have been growing substantially the past several days. A cornice fall right now has the potential to trigger a large deep slab avalanche. This is one more reason to steer clear of runout zones.