Observation Date: 03/18/2014

Route/Location:
7 miles up Bass Creek Canyon, Bitterroot Mountains. Skiing east and north aspects.

Weather:
Overcast with periods of light snow. 6-8″ of new snow overnight. Sun broke out occasionally, although for very short periods. Windy.

Wind:
Strong winds predominantly out of the WNW, although swirling throughout the canyon. Wind loading was evident at mid high and low elevations.

New Snow: 3-6″

Snow Density:

Avalanche Activity:
The main layer of concern today were dense wind slabs at mid to upper elevations on north, east, and south east aspects. The mid elevation (6000′-7500′) wind slabs were most concerning as they are sitting on a hard crust. I ski cut one of these on the leeward side of a ridge, east facing at 6500′, and it failed cleanly and with a lot of energy. Although only 8″ deep the slab picked up speed extremely quick as it ran on the crust bed surface.

It is worth noting that there seems to be layering with multiple wind slabs at this elevation. After triggering the first slab that ran on crust, I cautiously made two more turns down the run. At this point I heard a loud collapse and decided to bail on the slope ski cutting my way, next to but under the cornice, back to the safety of the ridge. As I neared the ridge there was a third, loud, collapse with propagation. It propagated an estimated 18″ deep, under the crust; but did not run. This could be a wind slab from last weeks wind event and something to be mindful of when on leeward terrain.

Wind slabs at upper elevation were prevalent, although no collapsing, propagation, or avalanches were observed. No crust above 7500′.

Other Comments:
Although there are wind slab issues right now we were still able to find enjoyable, steep powder in select locations. At mid elevations, where not affected by the wind; the 8″ of snow was light, sluffing on top of the knife hard crust.

Observer: Blake Votilla