Northern San Juan

Avalanche

Konigsberg, Hodgetts, Davis · Feb 5, 2022 · Northern San Juan

Weather

There was some snow moving at the highest elevations. Reports of transport and thin wind slabs forming around Silverton. Clear skies and cool temps.

Snowpack

We found a 170 cm deep snowpack on a northeast facing near treeline slope. This was near ridgetop so probably deeper than the average snowpack in this area. The basal facets are still fairly soft (four-finger hard) but hard to effect under a pencil-hard slab. The most concerning layer for the future is very soft near surface facets in the upper snowpack. The near surface facets are buried by about 4 to 5 inches of recent snow (in sheltered areas) and up to a foot deep (in drifted areas). If you found a small wind loaded pocket near ridgetop, you can trigger a small avalanche failing on the weak snow beneath. We also dug on a west-facing slopeand found a very shallow snowpack (less than 1 meter) but just a thin layer of basal facets near the ground. This slope was lightly drifted so we were able to get an easy result in a compression test on the facets buried under new and drifted snow.---It was easiest to trigger small sluffs on the most sheltered northerly-facing slopes. On a east-facing slope near ridgetop, there was a very hard crust under about 12 inches of drifted snow. As we descended the east-facing slope, the crust became less supportive and the facets below the crust were much weaker. Not an issue for now but we discussed how future avalanche issues would be most prominent in areas down off of the ridge, where more-fragile crusts and NSF is most intact, without previous wind battering.

Avalanche

We easily triggered small Loose Dry avalanches on north and east. They are snow moving and do not cause much of an issue if you are aware. We saw a person trigger a small wind slab on a steep northeast-facing slope in a confined terrain feature.