Observation: Upper Days

Observation Date
Observer Name
Brian H


Location Name or Route
Upper Days Fork
Wind Direction
Wind Speed
Snow Characteristics
New Snow Depth
New Snow Density
Snow Surface Conditions
Dense Loose
Snow Characteristics Comments
Slabby in wind affected locations, but protected areas still kept soft powder. There was still some graupel sitting on the snow surface in leeward areas, but despite this in protected areas the new snow did not seem upside down and a couple of quick pits confirmed this (see below).
Red Flags
Red Flags
Recent Avalanches
Poor Snowpack Structure
Red Flags Comments
Lots of cracking and collapsing in the new snow today, failing on the interface between the new snow and the crust which developed over the last several weeks of high pressure. The crust which in turn sits on top of very weak depth hoar. The new snow is still powdery in protected areas, but in any wind affected areas on the eastern half of the compass, the new snow is forming wind slabs that readily propagate fractures a long distance. Even in areas well below the ridgelines, we experienced shooting cracks and collapsing. We skied a few runs on some of the lower angle shots in Upper Days Fork and experienced good riding conditions. While traversing Reed and Benson Ridge, we caused shooting cracks on slope angles in the upper 30's, but nothing that entrained signifcant snow down the slope. However, these areas were on concave slopes with classic wind loaded starting zones at the top. I think that if the slopes were any steeper or more convex, we would have triggered some sizeable avalanches. In short, we now have a slab capable of propagating a fracture, sitting on top of a weak layer. This is by definition the recipe for a slab avalanche. However, there does not seem to be a lot of energy or momentum behind these fractures. My concern is that once this slab begins to get buried by the next storm(s), a collapse will generate enough momentum to cause the early December crust to fail and dig down into the depth hoar, potentially going full depth. Also: don't let the new snow fool you into thinking there is coverage on south aspects. Heading up flagstaff shoulder was easy, safe travel, but coming back down toledo bowl was an adventure.
Snow Profile
Slope Angle
Today's Observed Danger Rating
Tomorrows Estimated Danger Rating
Snow Profile Coordinates