Quick report
- Red Flags
- Recent Avalanches, Wind Loading, Collapsing, Poor Snowpack Structure
- Red Flags Comment
- <p>Lots of red flags out there. Most noteworthy was a large, D3 avalanche that Dave was able to intentionally trigger along Laurel Ridge into Horse Creek (detailed in a separate report). No natural avalanches were observed. We observed isolated collapsing and soft slab formation on north aspects below treeline, and observed heavily wind loaded slopes near and above. Our poor snowpack structure is well documented but most of the pack prior to this storm cycle was faceted through to the ground. Winds this week have built slabs 1-3' thick on top. </p>
Dave Garcia doing a crown profile on the avalanche he intentionally triggered into Horse Creek.
Collapsing and shallow soft slab formation failing on buried facets below treeline.
Heavily wind loaded N and E facing slopes in Gold Basin.
Snowpack
- Instability Comment
- <p>The underlying snowpack is comprised of multiple faceted layers on northerly aspects and it's now overloaded with wind drifted snow. We've been tracking a layer of near surface facets that were buried on February 11 which has been the immediate layer of concern. We've been expecting avalanches to fail there first with the possibility of stepping down into facets/depth hoar beneath the Christmas Rain Crust. The avalanche we triggered in Horse Creek did both. With more snow in the forecast tonight, the danger will likely increase. </p> <p>Without receiving much snow, the current avalanche problem is wind driven. Hard slabs of wind drifted snow, 1'-3' thick exist on northerly aspects near and above treeline. It is difficult, however, to conceive of a wind slab problem that won't step down into a buried persistent weak layer. </p>
8" of snow during the week did freshen things up but it was blown wildly, especially during the first 4". The second wave laid down more evenly but we still encountered plenty of areas of wind stiffened surface snow interspersed with loose powder, even below treeline.