Upper Swift Creek

We rode the upper reaches of Swift Creek looking for recent avalanche activity. We did not ride in avalanche terrain - or thought we weren't, until we were surprised by two recent piles of avalanche debris that crossed the snowmobile trail.  These destructive slides appear to have created new avalanche paths. 

• The slab avalanche activity we saw was confined to a mile-long stretch of steep, recently logged slopes at 5800-5900 feet. Including the two slides mentioned above, we tallied 8 recent natural or remotely-triggered slides in this area, all large or destructive soft slabs. 
• We did not find a particularly alarming snow structure in small column tests on slopes below this concentration of avalanches - no buried surface hoar at the January Drought surface. It could be that stratus/ fog levels created significant cvariability across short distances.
• We saw scattered loose snow slides, some from yesterday (2/21) and some from today, on steep, sun-exposed slopes. These generally released below steep, rocky areas.

Good riding in non-avalanche terrain! Lots of people out enjoying it.

Media forthcoming 2/23

We mostly traveled on roads or trails that had already been ridden.

2 test profiles at ~ 5250 feet, just below the steep slopes that avalanched showed roughly 45 cm of recent snow above two crusts. The crusts varied in thickness and distance between them:

on an east facing slope, the crusts were separated by 1-2 cm of soft small rounding facets. small column tests failed in this soft layer (CT 18-22 SP/RP x3)

On a northeast-facing slope, the crusts were separated by 2-3 cm of rounding facets. Similar results in CTs.

We could not identify buried surface hoar in either set of tests.