Aspen
AvalancheDylan Craaybeek · Mar 1, 2023 · Aspen
Weather
18F at the base of Dinkle Lake road at 8100ft at 9:00, Overcast and S-1. Snow increased throughout the day and the cloud base was right around 9800ft. so visibility was very poor and snow increased to S2 or S5 while in the clouds. Wind was consistently Light to Moderate with occasional strong gusts primarily from the north-northwest. Intense snow transport at ridgeline. Sun came out back at the trailhead at 16:00 with blue sky above Carbondale.
Snowpack
The new snow from the past few days quickly settled into a 1F to P-hard (on the hand hardness scale) cohesive slab on top of a slowly healing persistent weak layer. On wind-sheltered slopes this slab was around 50-60cm thick and extended column tests (ECT) were getting propagating failures between 10-15 taps. On wind-loaded slopes the slab was around one meter thick and ECTs would get propagating failures below this layer with 20-30taps. The only collapses and cracking all day occurred on wind-loaded slopes below the treeline where the total height of snow (HS) was less than one meter. Above about 9,600ft. the average HS was 200cm fairly consistently and increased to 250cm above about 10,500ft. as you get above Thomas Lakes above the trees. The snowpack here is similar to most of the Elk range where the spatial variability of weak layers is largely determined due to HS. On partially wind-scoured slopes or shallow wind-sheltered slopes where the HS was less than two meters the snowpack was significantly weak and more concerning and snowpack tests helped confirm the instability. The primary concern is the new/olds snow interface of mixed forms (facets and rounds). Although this weak layer is showing clear evidence of rounding and gaining strength it will be a concern for several days to weeks on shady northerly and east-facing aspects. Southeast slopes had a melt-freeze crust/facet combination on the few southeasterly slopes I dug on and easily got propagating failures in ECTs around 10-15 taps.
Avalanche
Observed several recent crowns from small slab avalanches on wind-loaded slopes and observed one large crown below the ridgeline during a period of visibility as well as seeing a natural avalanche that seemed D2 in the poor visibility fail below the ridgeline on a northerly-facing slope.