Observation: Snowbird periphery

Observation Date
3/7/2018
Observer Name
B
Region
Salt Lake » Little Cottonwood Canyon » Snowbird periphery
Location Name or Route
Lower Mineral Basin
Weather
Sky
Scattered
Wind Direction
West
Wind Speed
Light
Weather Comments
Light to calm variable winds with no transport and or wind blown observed. Temperatures rose rapidly and were 10 to 15 degrees warmer than previous day. Clear skies in the morning gave way to variable of high complete/thin cloud cover to scattered.
Snow Characteristics
Snow Surface Conditions
Dense Loose
Wind Crust
Melt-Freeze Crust
Damp
Snow Characteristics Comments

Riding/snow surface conditions became much more variable today with southerlies having m/f crusts from 3/6. Mid morning solar and warm ambient were able to get start getting slopes damp by 1000, and wet by mid afternoon. The cold snow riding was holding up on ENE through N through NNW, but the snow was much more dense/thick than on 3/6. The window for cold dry snow on Thursday will continue to narrow and to NNE, N and NNW, and only slope angles > 25 degrees will survive. Challenging early morning riding and spring conditions are here, and with the large accumulations of snow from the latest event, supportable crusts may not be in place for a number of days.

Red Flags
Red Flags
Recent Avalanches
Rapid Warming
Poor Snowpack Structure
Red Flags Comments
Poor snowpack structure in the periphery terrain out side of the deepest areas away from just the upper Cottonwoods continues to be illustrated by remote, human triggered and explosive triggered avalanches. See observations from past 48 hours, and on 3/7 avalanche control in the Cottonwoods was able to trigger an R3, D2.5 slide on an easterly facing slope by initially releasing a large cornice.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments

See observations from Major Evans times two, Mill Peak, and explosive control avalanche cited above.

Avalanche Problem #2
Problem
Wet Snow
Trend
Same
Problem #2 Comments

At 1300 widespread roller balls were active on steep SE, S, and SW at upper elevations. Plus numerous natural wet loose slides were observed on Superior, and other slide paths on south facing terrain in LCC. The forecast for more sun and even warmer temperatures may allow this problem to continue on Thursday during the peak of daytime heating.

High consequence moderate still appears to be the danger in isolated/outlying areas outside of the upper Cottonwoods. Natural wet activity could be called considerable during the peak hours of daytime heating and solar.

Cornice Concerns appear to be a definite problem to be aware of over the next 48 hours, and these could easily trigger large slides in many locations if they release either naturally and or by human triggers.

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