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Observation: Bear Trap

Observation Date
1/30/2016
Observer Name
Toddeo
Region
Salt Lake » Big Cottonwood Canyon » Bear Trap
Location Name or Route
Mill D to Beartrap
Weather
Sky
Obscured
Precipitation
Heavy Snowfall
Wind Direction
West
Wind Speed
Moderate
Weather Comments
Blustery day with some partial clearing late in the afternoon. Wind was transporting snow down to 8000'. PI >1" per hour at times.
Snow Characteristics
New Snow Depth
8"
New Snow Density
Medium
Snow Surface Conditions
Powder
Snow Characteristics Comments

8" new above 8000' feet or so, I think there is as much snow at 4600' in cottonwood Heights as there is at the Spruces, my car at the mouth of BCC had more snow on it than my partners car at the Spruces. Snow was dense at the base which prevented bottom feeding. It looks like storm came in warm, new snow was fairly well bonded to the underlaying crust.

Red Flags
Red Flags
Heavy Snowfall
Wind Loading
Cracking
Red Flags Comments
PI rates >1" per hour at times warranted caution. Wind loading was the primary concern today, snow was drifting down to 8000'. Enough snow blowing around on south aspects to obscure our skin track on one lap. Minor cracking due to a slight density inversion that I believe is wind related, localized and minor. Snow surface on the ridge between Shortswing and Beartrap was bit thick with some drifting.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Same
Problem #1 Comments

Wind slabs in exposed areas are my primary concern. While, I did not see anything alarming in the MIll D area, I would expect that there was enough wind today to increase the hazard to perhaps considerable in wind exposed locations.

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

I've seen enough reports of activity, including repeaters to keep this on my mind while traveling. With the exception of heavily wind-loaded features, I don't think todays storm added enough weight to increase the hazard for deep slabs.

Snow Profile
Aspect
South
Elevation
9,000'
Slope Angle
25°
Comments

Snow profile was only the upper 80 cm of a impressive 120 cm snow depth for a mid-elevation south aspect. I dug the pit to look for faceted grains surrounding crusts, but did not find anything alarming. Of note are the many crusts interlayered with a strong mid-pack. My partner commented that this profile looked more like the profile on s south aspect in BC rather than the Wasatch, it seemed stronger than I have seen in this location over the years. ECTN on many quick columns.

My hazard is based on a worst case scenario in wind loaded areas, moderate elsewhere.

One note on shortswing, over the last few years there has been a trend for the skintrack to ascend the far lookers right of this area instead of on the central ridge. Folks should note that area has avalanched with debris well into the trees. I am not sure how this trend started but it is worth noting in hopes that some of the newer skiers using this area will change their habits.

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