Vail & Summit County
SnowpackDrew Gibson Andrew McWilliams · Feb 16, 2024 · Vail & Summit County
Weather
Overcast and mostly calm below treeline. S-1 to S1 snow with a few periods of S2 during the day.
Snowpack
The snowpack is generally deeper than areas to the south in the Central Sawatch range with over 2m on northerly terrain and over 1m on southerly terrain near 11,000ft. In more wind-affected areas there is a 4F to 1F hard mid-pack layer on the N and NE resting over basal facets. What is more concerning are two persistent weak layers in the upper layers of the snowpack that are easily effectible on skis and snowmobiles. One layer is the early February near-surface facet layer and the other is a buried surface hoar layer that has been shown to be reactive in various locations. So far, it has not been the widespread culprit of many avalanches due to the lack of distribution and a cohesive slab resting over it. These layers seem to be reactive in locations that have received higher snow totals, areas that have been affected by the wind or have had warmer temperatures/received a bit more solar radiation allowing the slab to consolidate. Extended Column Test scores on N to E to S aspects were in the low to moderate range with propagation on buried surface hoar, buried near-surface facets, or around facet/crust interfaces. Easy to moderate failures also occurred on the basal facets with a little extra effort. Propagation Saw Tests showed failures to the end of the block (100cm-150cm total) with cut lengths of 30cm-35cm on the buried surface hoar and the buried near surface facets. The snowpack structure differs some from areas like the Gore Range and the Flat Tops Mountains, but depth and general problems are similar. The amount of recent snow on top of the buried weak layers is similar in the 60cm-70cm range, as is the hardness of the overlying layers and the reactivity of the weak layers. Some cracking and collapsing was observed on isolated terrain features where we were able to affect the basal weak layers.