- Submitted by
- ruari.macfarlane
- Observations date
- Saturday, January 14, 2017 at 02:30
- Location
- 49.007190° N 114.073860° W
- Reporting on
- Snow conditions
%2F-114.07386%2C49.00719%2C8%2C0%2C0%2F1026x200%3Faccess_token%3Dpk.eyJ1IjoiYXZhbGFuY2hlY2FuYWRhIiwiYSI6ImNqd2dvZmUxdzE4ZWg0M2tkaXpuNG95aTQifQ.pBLM87fE3sIxRJqJT7Bf7g&w=1200&q=75 "Forum Lake")
Quick
Avalanche
Snowpack
Weather
Incident
Information
- Avalanche date/time
- Friday, January 13, 2017 at 10:00
- Estimated occurrence time of avalanche
- Less than 12 hours ago
- Number of avalanches in this report
- 1
- The size of avalanche
- 3
- Slab thickness
- 180cm
- Slab width
- 90m
- Avalanche Character
- Deep persistent slab
- Trigger type
- Natural
- Start zone aspect
- N
- Start zone elevation band
- Alpine
- Start zone elevation
- 2,251m
- Start zone incline
- 35°
- Runout zone elevation
- 2,000m
- Weak layer crystal type
- Depth hoar
- Crust near weak layer
- Yes
- Vegetation cover
- Open slope
Comments
A small windslab avalanche during high winds on Thursday night ran over a shallow area in an open, wind affected bowl, triggering a much larger Deep Persistent Avalanche. This failed near the bottom of the snowpack - likely in large loose depth hoar crystals, perhaps in conjunction with a crust from the warm spell in early November. The snowpack depth was highly variable in the area the avalanche initiated, with the crown quickly increasing from (estimated-only saw this at a distance) 30 cm to 200cm! The fact that it only took a small windslab to trigger this makes me wonder if a human would, riding the same/similar slope... It's definitely a tricky problem to assess, and I'll be shelving any plans to step out into big open terrain this weekend.
