Observation: Mineral Fork

Observation Date
2/6/2014
Observer Name
Greg Gagne
Region
Salt Lake » Big Cottonwood Canyon » Mineral Fork
Location Name or Route
Mineral Fork
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
West
Wind Speed
Light
Weather Comments
-10C with occasional gusts of wind out of the NW. A brief 5-minute period of S1 snowfall.
Snow Characteristics
Snow Surface Conditions
Powder
Snow Characteristics Comments

Storm snow over the past week has settled into a very soft 30-45 cm (1' - 1.5') blanket of decomposing fragments. HS roughly about a meter at 9000', although was finding selected spots with nearly 1.5 meters at higher elevations.

Red Flags
Red Flags
Recent Avalanches
Poor Snowpack Structure
Red Flags Comments
Persistent and deep slab issues remain. Also saw debris from what appears to be a natural class 1.5 slide that started in very steep, rocky terrain.
Avalanche Problem #1
Problem
New Snow
Trend
Increasing Danger
Problem #1 Comments

Could really be either persistent or deep slab. Am calling it persistent slab as I am finding the weakest snow to be in the upper 50 cms of the snowpack. With large amounts of water weight expected, increasing danger is likely.

Snow Profile
Aspect
North
Elevation
9,300'
Slope Angle
Unknown
Comments

First time touring in the Wasatch in nearly two weeks, so my eyes were wide open for how the snowpack looks after the recent stormy period. Also the first time I have been in Mineral Fork this season. Overall the snowpack seems relatively stable with 30-45 cms of soft settled snow atop a poor snowpack structure.

My goals today (ok, skiing powder, but after that) were to identify potential weaknesses in the snowpack ahead of what appears to be a warm, moist stormy period.

Lots of quick pits today and the biggest concern I was identifying are facets forming between and below rain and rime crusts, now buried 30-45 cms down. The storm snow is quite soft and not a cohesive slab, but I was getting sudden collapses with compression tests in the weak faceted snow between and below these crusts. I realize the range of the crusts varies with respect to elevation and drainages throughout our range however.

Also found debris from a class 1.5 slide which I reported in the Avalanches section of the UAC site.

In rocky areas I was finding predictably weak snow with widespread facet gardens.

Going forward, there is plenty of soft snow available for wind transport, and this soft snow is likely to form the weakest layer in our snowpack with any new loading. Beneath that, faceted snow - especially around the crusts I was identifying - forms another weak layer. Didn't look at the snow near the ground all that much, but down about 50 cms from the snow surface I am finding a relatively stout 1F or P hard slab.

Video

Photos are from debris I noted from a slide that likely occurred on Wednesday, but details are sketchy at best. I reported this in the Avalanches section of the UAC site.

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