Observation: Ogden Mountains

Observation Date
12/10/2013
Observer Name
Evelyn
Region
Ogden » Ogden Mountains
Location Name or Route
Ogden Mountains
Weather
Sky
Broken
Wind Direction
West
Wind Speed
Moderate
Weather Comments
Ridgelines were 45 to 50 mph, westerly. Mid elevation terrain, southwest, 15 to 20 mph.
Snow Characteristics
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments

Lots of wind damage, upper and mid elevations, with breakable medium to hard slabs, with a very few hard-to-find patches of soft powder mixed in.

Red Flags
Red Flags
Recent Avalanches
Wind Loading
Cracking
Collapsing
Poor Snowpack Structure
Red Flags Comments
Lots of cracking, of the new surface winds drifts. Locallized collapses on smaller test slopes. While the surface wind slabs were certainly collapsing, it also seemed that some of the collapses may have been deeper - either between the two recent storms or on the mid pack facets.
Avalanche Problem #1
Problem
New Snow
Problem #1 Comments

These would be the deeper, trickier avalanches. More likely to trigger on wind drifted slopes.

Avalanche Problem #2
Problem
Persistent Weak Layer
Problem #2 Comments

Lots and lots of cracky wind slabs - on a wide variety of aspects and mid to upper elevation slopes. Many in the 6-10" range, but I suspect deeper slabs are certainly out there.

Comments
  • Snow pit at 8,400', on a NNW facing slope. (Photo Below) I feel like this is a fairly representative pit of the mid elevations, though this was my first day in the Ogden area mountains. Weakest layer was the facets that formed during the late November dry spell, with the snow from the last two storms creating the slab. Many areas also had a 6" wind slab on top.
  • There is also a facet layer near the ground, and while tests weren't failing on this layer yesterday, I would continue to dig to the ground. I still think that the basal facets could be a player in the future, or even in isolated areas now.
  • Snow pack layering and depth were more similar to the Salt Lake mountains than I expected.

Interesting layering on a lower elevation NNW facing slope - 7,300'. (Photo Below) A significantly weak layer of facets sitting on a hard, melt/freeze crust. A classic weak layer/bed surface combo, with a just a thinner slab on top at the moment. Multiple hand and pole pits had it popping out on this layer, on isolation or with a light tug. Again, the slab is the snow from the most recent two storms.

While there may not be too many "big" avalanche paths at this elevation, it has me thinking about low elevation terrain traps, such as creek beds androad banks cuts where even a small slide could stack up a bigger pile of debris.

Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable