Sky: overcast with occasional clearing and scattered valley fog
Temps: mild, in the mid to high 20s F
Obvious Signs Of Instability
Older wet loose avalanches and rollerballs on the North side of Cornbiscuit and
S facing in Superbowl that likely occurred during the warm up on Feb 12th.
1,000-2,400’ – thin crust above 1” recent storm snow
2,400-2,800’ – 3-4” settled storm snow
3,000-3,400 – 4-5” settled storm snow
Very small surface hoar (.5-1mm) formed overnight at all elevations in open terrain.
Steep South facing terrain now has a firm sun crust which formed on Feb 12th.
Snow below the surface
Our focus today was on assessing the depth and distribution of the most recent
storm slab. Slabs were first encountered around 2,400’ and existed in small
pockets all the way to ridgetop level (3,400’).
We dug just below the ridge in PMS bowl and found slabs to be on average around
8” thick. Tests showed moderate to high strength and low propagation potential.
Facets (1-2mm) sitting below this slab sit on older firm snow.
Around the 2,800’ level those facets are larger (2-3mm) and more well developed
and sit on a crust. In the mid elevations where slabs exist (which were very
shallow and unconnected across slopes in this location), a greater potential
exists for wide propagating fractures.