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Observation Date
4/15/2015
Observer Name
Toddeo
Region
Salt Lake » Big Cottonwood Canyon » Brighton Perimeter
Location Name or Route
Brighton Perimeter, Milli Area
Weather
Sky
Obscured
Precipitation
Moderate Snowfall
Wind Direction
West
Wind Speed
Strong
Weather Comments
Windy day with occasional calm spells. A few bright perods but no direct sun from sunrise until my exit at 1.30. No greenhousing.
Snow Characteristics
New Snow Depth
15"
New Snow Density
Low
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments

14-16 new above 9,500'. 12" at the base of Brighton, right side up and low density, mostly stellers. Of note: above 9,500' the basal 10 cm is slightly damp, my guess is that the first pulse came in warm and perhaps only at the higher elevations.. No major density inversions.

Some soft wind crusts/drifts in places.

Red Flags
Red Flags
Heavy Snowfall
Wind Loading
Cracking
Rapid Warming
Red Flags Comments
Snow up to 1-2" per hour (S2-S5) at times. A few observed point releases, nothing major. A lot of wind transport, we had to break a new trail on every run in places. Tracks in exposed areas were filling in every lap. Some drifts up to 3' deep. A lot of soft cracking, no shooting cracks. Cracking was picking up later in the morning and early afternoon. I would not be surprised if there are some sensitive wind slabs in the higher exposed terrain, which we did not travel through today, due to concerns about the red flags observed (and the fact that visibility was really poor!). I included rapid warming more as a red flag to be aware of tomorrow, there is a lot of new low density snow that will be very sensitive to heating tomorrow.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments

Moderate in the terrain we traveled in today but I would not be surprised if the hazard is higher in the alpine. I observed enough drifting, cross loading and soft cracking to be concerned.

Avalanche Problem #2
Problem
Wet Snow
Trend
Increasing Danger
Problem #2 Comments

This will be a major concern as soon as the sun even thinks about coming out.

Considerable, and with the new dry snow/ high April sun angle combo, perhaps a bit easier to forecast than usual.

Snow Profile
Aspect
North
Elevation
9,600'
Slope Angle
25°
Comments

Snow profile only illustrates the storm snow, didn't feel the need to excavate through the knife hard mid pack (forgot my chainsaw....).

Why didn't we get storms like this in January/February?

Tomorrows' considerable rating is mostly due the sun coming out.

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