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Observation: Mule Hollow

Observation Date
2/19/2018
Observer Name
B
Region
Salt Lake » Big Cottonwood Canyon » Mule Hollow
Location Name or Route
Mule Hollow/West Willow
Weather
Sky
Obscured
Precipitation
Light Snowfall
Wind Direction
Southwest
Wind Speed
Light
Weather Comments
Frigid temperatures dropping all day. Winds accelerating in the late morning hours and was moderate speeds when gusting, and out of the SW. Tranport was light. Light snowfall during the day with accumulations of 3 inches at 1700 hours.
Snow Characteristics
New Snow Depth
15"
New Snow Density
Low
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments

New snow overnight was 14 inches at 8000. The first 4 inches were very light density and it appeared that the final 10 inches stacked up with heavier densities due to the high rates of PI. As a result the new snow was slightly inverted and low angle riding was slow, bottom feeding, and not great. Slope angles > 25 degrees offered better riding.

Red Flags
Red Flags
Heavy Snowfall
Wind Loading
Cracking
Red Flags Comments
8 inch thick soft slabs were widespread due to the inverted nature within the new snow. Southerly facing slopes with prestorm m/f crusts that served as excellent bedsurfaces and with poor bonding. The previously mentioned initial layer of light density snow served well as a reactive weak layer. Cracking in the new snow was observed on slopes with angles 35 degrees and greater.
Avalanche Problem #1
Problem
New Snow
Trend
Decreasing Danger
Problem #1 Comments

See above

Avalanche Problem #2
Problem
Wind Drifted Snow
Problem #2 Comments

Observations today and remote weather stations confirmed the increasing winds, and subsequently the wind slab problem appeared to be increasing in danger as throughout the day. The wind forecast appears to keep the speeds high enough to keep wind blown possible with the ample supply of snow available for transport. This problem will at the very least continue to maintain the same trend wise.

Along with these two problems, Persistent Slab concerns can not be ruled out, especially in the outlying terrain where the snowpack is thinner and weaker. the quick inch of water may have been enough in isolated areas today to have reactivated the buried weak layers.

If the winds do not contribute to make stability worse, the danger for Tuesday appears to be high consequence moderate.

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