Avalanche

Upper Slate and Washington Gulch areas.

Evan RossGunnison
View on map
Observation photo 1Observation photo 2Observation photo 3Observation photo 4Observation photo 5

Quick report

Cracking
specific

Obvious signs of instability with shooting cracks on wind-loaded terrain features and a couple more on wind-sheltered slopes.

Weather

Cloud Cover
broken
Wind Loading
moderate
Recent Snowfall
5 to 30
Snow Avail For Transport
moderate amounts

The weather was alternating between obscured sky and snowing, to broken with periods of sun. New snow today probably added up to an inch or two. Active wind-loading occuring at upper elevations.

Snowpack

In the valleys of Washington Gulch and the Slate River, the crust from last week is down about 5 to 10cm on average. That was due to either settlement or just lower snow totals at lower elevations. Recent storm totals of around 11,500ft are in the 20 to 35cm range.

Wind slabs were the most common avalanche problem, with loose snow avalanches coming up next. There was a new snow instability within the storm snow that could have produced a wind slab on southerly-facing slopes, otherwise, the new snow was bonding ok to the old crusts in those areas. The only places I was able to get notable results were on ENE and NE-facing slopes, where the old snow interface consisted of small facets on a crust. Those small facets were not common across all east-facing slopes and quickly became more common once you turned north of about 65 degrees.

The head-scratcher would be why those two somewhat wind-sheltered NE-facing slopes produced storm slabs when other NE-facing slopes just produced sluffs. Perhaps those slabs had a slight bit more wind effect to add some cohesion to the storm snow. Otherwise, while the weak layer was more consent on those aspects, the cohesion in the storm snow was more variable and the driving factor for slab avalanche release. 

Avalanche

Size
D1.5
Type
SS
Aspect
NE
Trigger
AM
Elevation
11000 ft

Small sluffs on steep northerly to easterly facing slopes. Triggered 1 small wind slab on an ENE facing slope at 11,200ft and 2 other small storm slabs on NE facing slopes at 11,000ft.