Observation: Mineral Fork

Observation Date
12/27/2013
Observer Name
Trent Meisenheimer
Region
Salt Lake » Big Cottonwood Canyon » Mineral Fork
Location Name or Route
Mineral Fork - Moonlite
Weather
Sky
Clear
Snow Characteristics
New Snow Density
Medium
Snow Surface Conditions
Powder
Dense Loose
Wind Crust
Rain-Rime Crust
Snow Characteristics Comments

Out of all my travels in the Central Wasatch, Mineral Fork had the worst rime crust I have seen this year. On the windward side of the ridges or hills the rime crust was stout and strong. On the sheltered side it was still present but more breakable and allowed for ok riding and turning.

I suppose as you moved up higher in elevation the rime crust would be thinner and less of a problem, just speculation on my part.

Red Flags
Red Flags
Poor Snowpack Structure
Red Flags Comments
Avalanche Problem #1
Problem
New Snow
Trend
Same
Problem #1 Comments

Mineral Fork had some of the weakest faceted grains that I have observed in the Central Wasatch. Starting at the ground the basal faceted grains had some strength to them. However, It was the faceted grains about 10 inches up from the ground that fell right out of the snowpit wall.

Further complicating the issue a 1 finger dense slab sat on top of those very weak grains. Again this slab seemed stronger to me than other areas I have been in around the Wasatch. Perhaps Mineral Fork had stronger localized winds that created a more stout slab, than other neighboring drainages up canyon?

My ECT results were in the 21-25 tap range, but the shear quality was alarming, very clean & high propagation propensity. PST 30/150 very lively propagation all the way up the column (see video)

Triggering an avalanche right now would be like pulling the bottom log out of the log pile, sending the whole hill down on you.

Comments

Mineral Fork coverage is still pretty thin. Most of the east facing terrain averages 60-70 cm deep with spots of 100 cm.

This rime crust was present up to 9100 ft on the northeast & east facing aspects. Did not travel any higher.

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