Our Fall Auction is LIVE! Support avalanche forecasting by bidding TODAY! Ends Sept 26th.
Ad
The National Forest Service Logo
icon-add Observation
Forecasts
Logan Ogden Salt Lake Provo Uintas Skyline Moab Abajos Weather Archives How to read the forecast
Observations & Avalanches
Submit Observation Observations Explorer All Observations Avalanches Fatalities Weather Place Names Map Archives
Education
Avalanche Class List UAC Class List Online Classes Resources and Tutorials Avalanche Awareness Develop Skills
Events
Store
About
Contact Who we are Core Values Staff Board of Directors Past Forecasters Sponsors Annual Reports Sign In
Blog
icon-add Observation
Donate / Join

Observation: Brighton Perimeter

Observation Date
2/22/2017
Observer Name
B
Region
Salt Lake » Big Cottonwood Canyon » Brighton Perimeter
Location Name or Route
Brighton Periphery
Weather
Sky
Obscured
Precipitation
Moderate Snowfall
Wind Direction
West
Wind Speed
Light
Weather Comments
Light snowfall in the morning hours, and then the rates increased in the late afternoon to S3 plus for a number of hours. Winds were mostly calm until around 1400 when they increased to light. Temperatures remained in the mid 20s at 9000.
Snow Characteristics
New Snow Depth
16"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments

14 inches of right side up snow at the start of the day, and then it appeared to snow another 4 to 6 during the day. The riding was reported as "one of the best days of the year". Low angle riding was fast and silky and moderate to steep lines were light and face shots were happening.

Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Poor Snowpack Structure
Red Flags Comments
Poor Snowpack structure was observed within the new snow. There was a slight density inversion 6 to 10 inches down. This was easily felt trailbreaking, though it wasn't difficult. The biggest part of this structure was how it allowed for widespread sluffing and easy to trigger soft slabs that were so soft they were vacillating between sluffing and airy storm slabs. Of Note: Any slopes with angles 40 degrees and > were self releasing in the new snow only. And, the winds appeared to pick up slightly around 1400 and they were helping initiate a widespread Loose Snow Avalanche Cycle. See avalanche observations for details.
Avalanche Problem #1
Problem
New Snow
Trend
Increasing Danger
Problem #1 Comments

See above and avalanche observations. With the forecast for additional accumulations overnight and during the day tomorrow, these Storm Slabs may be reaching depths of at least 2 feet. Of Note: Slick crusts exist on many slopes on the lower half of the compass and this may allow increased and faster running new snow avalanches.

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

Though the forecast for the winds are expected to remain mostly on the light side, the new snow is such light density that transport is very possible. The Loose Snow Avalanche Cycle reported in an other observation spoke to this potential.

And, with the large slide reported from the Mary Chutes, Persistent Slab issues may be resurfacing with these new loads. Lingering facets that have been observed at the rain crust/melt freeze crust from the beginning of February have been observed by many others and their previously dormant state may shift to reactive in isolated areas.

Danger rating today appeared to be Considerable. And, during the possible intense periods of precip that may be occurring during the day on Thursday it may spike to High.

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