Avalanche: Chugach State Park

While touring up Hanging Valley (Whumpfing Valley), multiple very large whumpfs were heard mostly on 1.5-2’ of wind packed new snow over concavities in the valley.

Multiple fresh D 1.5 crowns were noted on various aspects primarily above and below cliff features.

We dug two pits in the valley and found no propagation, but easy failure in the top wind/storm slab (20cm) and medium energy failures down ~40cm at a very slight interface within the new snow. The new snow on top of the hard layer did not show much energy.

We proceeded to dial back risk and cautiously toured up mellower slopes towards Eagle River Overlook. Multiple massive whumpfs were heard culminating in a whumpf that continued for 5-10 seconds propagating all directions that sounded as though it was echoing off the cliff walls in the distance. Possibly 5 seconds later, we witnessed a short, very wind loaded ridgeline release with an average crown height of 2’. We measured our distance to the crown at 2000’. We found a second crown downslope around the corner on a less wind loaded aspect to have also released on a similar scale.

We did not investigate the crown directly. Winds were blowing from the S 20-30mph, making for a chilly environment. Skiing isolated slopes back down to the valley, snow was significantly less wind affected. Another natural release was noted across the valley adjacent to a slide that had released prior to our arrival. While highly unlikely, there is a small possibility that our whumpf triggered this slide 2.5 miles away.