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Observation: Salt Lake

Observation Date
2/5/2018
Observer Name
B
Region
Salt Lake
Location Name or Route
Catherines Basin: Rocky Point and Sunset, Martha's Bowl, and East Facing Pioneer Ridge Shot
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
Northwest
Weather Comments
WNW winds were strong in the morning and until mid afternoon on the exposed ridgelines, and also getting down into the basins. By late afternoon the winds appeared to die down significantly, yet they were still moderate on the exposed ridgelines. Transport and or wind blown was moderate throughout the day. Temperatures overnight at 8000 feet once again did not dip below freezing, and rose to 40 degrees by mid day. At the upper elevations the temperatures moderated and remained some what cool with the overcast skies preventing excessive heating. As a result the southerly facing slopes did not crust and or get damp above 9000.
Snow Characteristics
New Snow Depth
3"
New Snow Density
High
Snow Surface Conditions
Dense Loose
Wind Crust
Melt-Freeze Crust
Rain-Rime Crust
Snow Characteristics Comments

Two to four inches of large (2+ mm) graupel covered the old snow surface, and the constant winds from the last 48 hours had helped break down the old tracks and smooth the surface out. The combination of this grooming by the wind and the graupel worked together to provide creamy carvable turning conditions. The low and moderate angle slopes rode the best, yet slopes of 35 to 40 degrees also rode well. The easterly aspects had the best riding conditions with fewer areas of wind crust and lingering old rime crust.

Red Flags
Red Flags
Wind Loading
Poor Snowpack Structure
Red Flags Comments
See above for wind loading details from the WNW winds, and eventhough the small isolated pockets of wind slab observed were stubborn and unreactive, it is likely that there were mid slope areas in more exposed terrain where this issue may have been more reactive and prevelent. Overall, the basal facets in the Brighton/Alta perimeter where the HS is approaching 2 meters appear to showing signs of rounding, and the warmth from the past week is also helping strengthen the mid and upper layers of the snowpack. Despite this tendency towards healing, shallow snowpack areas and specifically rocky areas still remain suspect. Of note, graupel runnels and subsequent loose dry sluffing, and graupel pooling under steep cliff band may present possible manageable issues for Tuesday.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Decreasing Danger
Problem #1 Comments

With no human triggered slides in over a week, this problem appears mostly dormant right now, and the minimal new load from this latest event did not appear to increase the potential for failure and propagation in the previously cited basal facets.

Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Decreasing Danger
Problem #2 Comments

See above, and the highest elevations appear to continue to have strong winds, so this problem may only be confined to the upper elevation exposed terrain.

Until the Persistent Slab issue has been put to bed permanently, the Danger Rating appears to be moderate.

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