Anna Creek: Swan Range East Side

We spent 2 nights at the Anna Creek cabin in the Swan Range. Due to a lean snowpack year, we were not able to access middle and upper-elevation terrain via snowmobile. 

• 4 to 6 inches of new snow fell between 2/7 and 2/9. Today (2/9), snow squalls produced snowfall rates of 2 inches an hour. We drove out of the precip on our way north today. 
• On 2/8 we easily triggered Dry Loose avalanches in 40+ degree terrain. Slides ran fast and far on top of a hard crust. These were specific to northerly aspects. 
  • Sluffing was easily mitigated with ski cuts. Steeper does not equal better. Sluffs would clean out all of the recent dry snow and leave just the crust to descend. Lower-angle slopes were more enjoyable. 
• On 2/9, roughly 4 inches of new snow fell overnight. We observed signs of wind-drifted snow near ridgelines above 6500 feet. 
  • Triggered shooting cracks up to 20 feet in length. Slabs of wind-drifted snow rest atop a layer of facets above a crust. This structure will make them slow to gain strength.
  • Slabs of wind-drifted snow averaged 8 to 10 inches thick and were soft. Today, these were easy to manage with ski cuts, or by tucking in lower down on the slope. I don't anticipate these slabs to be "easy to manage" in areas that received more snow, or as slabs continue to thicken.

media to come. 

North Aspects at Middle and Upper elevations: 

6 to 8 inches of faceted snow resting on a knife-hard crust. This snow is soft and cohesionless. Grain sizes average 1 to 2 mm. The 2/3 crust was 10 inches thick at roughly 6500 feet. 

East and Southeast Aspects:

We found a crust/facet/crust combination in the upper snowpack. A pencil-hard melt-freeze is near the surface with a soft layer of 1-2 mm facets below. This structure is resting on the hard 2/3 crust. 

South and Southwest Aspects:

These aspects appeared to have been cooked by the sun and warm temperatures on 2/6. Surfaces were crusted and we did not find the crust/facet/crust combination observed on easterly aspects.