Alaska Pacific University Snow Science 1 class toured in storm conditions to observe how the new snow is bonding with old snow surface.
On the way down to the pass, we happened to observe a natural avalanche running down to Turnagain Arm. This path is directly across the water from Girdwood Tesoro, off the peak 3849. The starting zone was in the clouds, so we have not that much data on avalanche specifics. There was no dirt in the new debris piling up & powder cloud was significant.
|Cracking (Shooting cracks)?||Yes|
Only localized cracking within new storm snow.
It snowed on us most of the day in the afternoon reaching rate up to 2 cm/hr. It was nice to see big fat flakes!
Visibility was poor most of the day so we ended up turning around at 2000'.
Temperature was hovering below freezing. North wind was moderate & making the snow move horizontally in the air.
Moist new snow on the surface, 5-10 cm depending on elevation. Old snow surface was quite supportable. At 2000', surface snow started feeling more windpacked, but we did not reach any ridgelines to assess full wind impact.
We observed small roller balls on steeper slopes below our skin track - makes sense with the moist, warm, storm snow.
Hand shear test showed some cohesiveness within the new storm snow. Small test slopes did not show expected storm slab releases, but this could be different on steeper (>35) slopes.
We were tracking several crusts within the top 50 cm of the snowpack with poletests on our skin up.
We dug a test pit at 2000' on a 28deg NW facing slope just above the last tree island. HS 265cm.
While snowpack seemed stable, we did get interesting results that concentrated below crust 65 cm below the surface. Upon taking a closer look, we found some faceted forms below the knife hard crust that kept acting as a layer of concern on all of our tests
Test results (all on the same layer): CT17RP, CT20RP, ECTP31RP, ECTP w Boot Crusher, PST64/100RP.