Turnagain Pass Avalanche Forecast

“Honking”… This was my favorite descriptor of the strong northwest winds pummeling the region yesterday. Well, those winds continued overnight and will keep honking through most of today. Ridgetops have been seeing averages from 20-40mph and gusts twice this. To add insult to injury for the second week of April, cold arctic air is being ushered in and the Sunburst weather station just hit -6F at 6am! When the winds come from the northwest they can sometimes split around Turnagain Pass, but unfortunately this isn’t the case this time. It’s likely going to be quite difficult to find any soft snow in anything but the most sheltered treed areas today.

Skies were a bit obscured yesterday with all the blowing snow. However, we can have a pretty safe bet there were several naturally triggered wind slab avalanches and maybe even some cornice falls over the past 24 hours. This possibility remains today with the continuation of the winds. Despite a limited amount of soft snow available for transport, the winds seem to be eroding harder old snow and finding a way to keep loading slopes.

If you do head out today, pay attention to active wind loading and slopes with recent wind deposited snow. Human triggered wind slabs will be likely. Slabs could be anywhere from a few inches thick to a few feet depending on the amount of loading. Watch for cracks that shoot out from you and stiff snow over softer snow. Winds may have impacted mid elevations treed zones or other areas not commonly affected. Remember, wind slabs that release could step down into buried weak layers and create a larger avalanche (more on that in Problem #2).

Winds blowing snow off the west face of Pyramid and loading the easterly face. 4.8.21.

Blowing snow in the Summit Lake region. 4.8.21. Paul Wunnicke.

Strong winds south of Turnagain Pass. 4.8.21. Paul Wunnicke.

With new wind loading occurring, we are suspect this might overload buried weak layers and cause them to become more reactive. There are a few layers of facets and buried surface hoar in the top 3′ of the snowpack. These layers have been showing varying degrees of strength and just enough weakness in places that we are still concerned a person could trigger a persistent slab avalanche. Shaded aspects are the most suspect places to trigger these now due to southerly slopes having various sun crusts. Knowing these layers are there, listening/feeling for whumpfing and watching for any other signs of instability are good things to keep in mind. As always, use good travel protocol, and consider the consequences if an avalanche does occur.