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Observation: Mill F

Observation Date
2/15/2016
Observer Name
Toddeo
Region
Salt Lake » Big Cottonwood Canyon » Mill F
Location Name or Route
Mill F
Weather
Sky
Obscured
Precipitation
Light Snowfall
Wind Direction
West
Wind Speed
Strong
Weather Comments
Warm and windy, wind was moving snow well below the ridgetops. Skin track was filling in every run in exposed places.
Snow Characteristics
New Snow Depth
5"
New Snow Density
High
Snow Surface Conditions
Dense Loose
Snow Characteristics Comments

5" or so of dense new snow, a good cover. 3-4" at the Guard Road trailhead and 5" in upper Mill F.

Red Flags
Red Flags
Wind Loading
Cracking
Poor Snowpack Structure
Red Flags Comments
Wind loading is my primary concern today, I did not venture to the PC ridge line but based what I saw at the Mickey Mouse Mine, I would expect significant loading, drifting and wind slab formation. Some minor cracking in the new snow, all localized. Poor snow pack structure consist of weak, faceted snow on north facing aspects. Some ice and rime on trees, storm looks like it came in warm.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Decreasing Danger
Problem #1 Comments

Based on some quick pits and ECT's on a small slightly wind exposed area which is often protected, I anticipate sensitive wind slabs in more exposed areas. I was able to isolate the new snow above facets with 1 exception. In in quick columns and ECTs, the new snow sheared easy and planer at the base of the new snow. ECTs were Negative, they broke in the middle with one of the sides shearing, no propagation, I don't think the slab was dense enough at this location.

I was not able to produce shears on south aspects, new snow seemed well bonded.

Considerable hazard in wind loaded areas.

In areas that did not receive much snow it could be a higher probability, lower consequence type of event.

Avalanche Problem #2
Problem
Normal Caution
Trend
Same
Problem #2 Comments

Normal caution for other potential hazards, could include warm weather travel protocols if the sun comes out as forecasted.

Comments

Old school ob today, no profile no pictures! Morning tour only, out at noon.

I think the hazard is dependent on the amount of new snow likely higher in LCC where it snowed more.

I would anticipate that the wind slabs settle out overnight.

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