Vail & Summit County

Temperatures in the 40s, not a cloud in the sky, and calm winds

The avalanche we saw on Ptarmigan Hill likely ran during intense northwest winds a few days ago, breaking down at the basal facets. There was no evidence of water penetrating the slab - this was a Persistent Slab avalanche. Some new drifting on the bed surface made it clear the slide was more than one or two days old. The basal facet interface is the layer of concern for Persistent Slab avalanches on north- and northeast-facing upper-elevation slopes. We got no result in an Extended Column Test, but a short cut-length to end on a Propagation Saw Test. Looking across the valley at low-elevation southerly slopes, they were mostly dirt, and these will likely be pulled from any problem rose soon as the volume continues to decrease and more bare ground starts to show. We didn't see any new evidence of wet snow problems, even though the temperature was in the 50s by the time we left.