Improving Dec 11 layer stability on Mt. Lola.

We headed to the NE ridge of Mt. Lola today and assessed some NW and NE aspect terrain as well as some E to ESE aspect terrain. All of it was near treeline or below treeline. Starting out from Little Truckee Summit, the recent rain cust at/near the snow surface made keeping snowmobiles running appropriately cool challenging but possible with care. Once we ascended above about 7,200' the rain crust became absent and riding conditions improved dramatically.

Snowpit data collected on a NE aspect above Independence Lake in between two avalanche path start zones revealed good strength gains on the Dec 11 layer. Digging into the snowpack I was initially concerned with the layering of P hard rounds over 4F hard looser large grained facets 1 m down at the Dec 11 layer interface. This is a common structure seen over the years at Sierra deep slab avalanche crowns. Snowpit tests (ECT, CT, DTT, and PST) did not reveal any evidence of continued problematic instability on the Dec 11 layer, matching with other recent observations from this zone. No other signs of instability were observed on the NW and NE aspects traveled.

Very minor amounts of drifting snow from NE winds were noted in open areas along the ridgetop. No problematic wind slabs were observed where this drifting snow deposited.

Snow surface melt was occurring on the E to ESE aspects in the elevation range of 8,000' to 8,700' that we traveled. Minor amounts of roller balls were noted but no significant amount of wet snow instability was present at 12:30 pm.