Vail & Summit County
AvalancheJaphy Dhungana · Feb 21, 2021 · Vail & Summit County
Weather
Wind Speeds: Moderate, 17-25 mph, with gusts up to 35mph Ridgeline Wind Direction: NW Wind Loading: Light Sky Cover: Broken Precip Rate: NO Weather Description: On and off cloud cover remained steady throughout the day. Moderate winds decreased after 1pm NTL, but looked like it remained constant at the ridge tops.
Snowpack
The snowpack was variable throughout the Saints John drainage, from bare ground on the wind-scoured aspects up to 150cm in sheltered areas. Sizeable cornices visible on the ridge tops. We dug 2 pits, on a N aspect, and another on an E aspect, both NTL. Below the upper new snow (PP) layer, ranging from 4-10cm, there is a strengthening slab, 4F to 1F. Below this is a continuous facet layer, and notable depth hoar at the ground. The snowpack is gaining strength, and none of the tests produced any results until well after 30 taps, at which CT results failed at the ground. Despite the lack of stability test results, the overall structure of the snowpack is poor, and we maintained wide margins on slopes >30*, connected slopes, and loaded overhead start zones. With the variable coverage observed in the drainage, the snowpack is primed for a trigger at the wrong spot (i.e, shallow trigger point). At NTL and ATL, there is definitely a wind-slab forming from the recent winds, but we did not venture to these areas to assess, since those zones are squarely in our "red-light" or "no-go" zones given the current conditions.
Avalanche
HS-N-R2D2-O. Approx 200' x 200'. East aspect, 12,000'. A wind-loaded slope just below the ridgeline. Difficult to note the crown and debris in the flat light, but it was obvious when the sun was out.