Sawatch
AvalancheDrew Gibson · Nov 21, 2023 · Sawatch
Weather
Warm, mostly clear, light, swirling wind above treeline.
Snowpack
The below treeline snowpack has been heavily affected by the warm temperatures leading up to the last storm with some slopes having no snow or only a couple of inches from this last storm. The same can be said of the sunnier aspects near and above treeline. There are small cornices and wind pillows on southerly aspects near the ridge crest, but the snow quickly tapers off once you move down the slope. Near and above treeline on the east and north aspects had five to eight inches of new snow. The wind has caused some havoc with some northerly aspects having been stripped down to the old snow surface, and others cross-loaded depending on the terrain characteristics. East aspects above treeline have been top and cross-loaded and the depth of the slab can be up to 70cm thick. Saltation rows were observed on some near ridge crest east and southeast slopes. On east and northeast aspects near and above treeline I was able to find the buried melt-freeze crust under the new snow. Once I moved to north northeast and north the crust was not present and the old snow surface was decomposing wind board or unsupportive facets on more sheltered terrain. Though the decomposing wind board was harder than the surrounding snow, the snowpack is overall soft, and columns crumbled during tests. Most north and east-facing wind pillows had shooting cracks when you approached them and multiple natural failures were observed.
Avalanche
The slide was triggered near a bush on the skier’s right flank. The slope angle at the trigger point was 25 degrees, but it rolled over to 31 degrees where the crown is the largest. The slope is small so the hard slab blocks did not break up. The failure communicated another 200ft beyond the left flank, into <25 degree, more north-facing terrain. The bed surface was a pencil-hard melt-freeze crust and was supportive on skis. The snow underneath the crust had variable depth depending on location and was completely faceted.