Observation: Salt Lake

Observation Date
2/9/2013
Observer Name
Greg Gagne
Region
Salt Lake
Location Name or Route
White Pine
Weather
Sky
Broken
Precipitation
Light Snowfall
Weather Comments
Windless. -10C at 10 am at 10,000'. S1 snowfall when exiting at noon.
Snow Characteristics
New Snow Depth
6"
New Snow Density
Medium
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments

This Colorado blockbuster was pretty good even by Wasatch standards. Moderately-dense new snow with some wind slabs > 10,500'. Ski and travel conditions were quite good.

Red Flags
Red Flags
Poor Snowpack Structure
Red Flags Comments
Like others, continue to find 4 or 5 lemon structure. Yet the slab on top of the two January faceting events doesn't seem to have energy right now.
Snow Profile
Aspect
Northwest
Elevation
10,500'
Slope Angle
32°
Comments

Quite a bit of spatial variability while looking at today's snow. Really just focusing from the snow surface down to the facets that formed Jan 1-8 which are buried roughly 60-75 cms (2-2.5') down. In the upper elevations this area has a relatively deep snowpack averaging about 2 meters, so the facets don't seem to be as advanced as in thinner snowpack areas. Regardless, not crazy about the structure.

We did push some slope angles, but only after carefully evaluating the slab on top. In general I am trying to avoid areas where I am finding recent wind deposits sitting on top of facets. In areas where we weren't always sure what the snow structure was like, we notched slope angles down and avoided steeper terrain. (Plus, lower angled slopes generally skied better today anyways!)

Was getting easy shears at the new snow/old snow interface, and was finding the new snow sitting on top of weaker faceted snow in upper elevation north-facing aspects. New snow instabilities have healed overnight and the new snow wasn't acting as a cohesive slab , so was not concerned about new snow avalanches this morning.

Did find Jan 30 rime crust on some NW aspects. It was 1-2 mm thick and fortunately was not finding faceted snow above or below the crust.

Friday night storm wasn't enough water weight and/or wind to suddenly overload weaker midpack layers, and by the looks of the Saturday afternoon Cottonwood Canyons update, forecasted amounts also don't seem to be enough to tip the scales. No collapsing observed at all today.

Did observe several natural sluffs in steeper terrain. Likely due to high PI rates when the storm came in. (Photo courtesy Rob Westermann.)

Coordinates