Avalanche Forecast
Issued: Nov 9th, 2019 4:00PM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeWatch for fresh wind slabs in steep terrain Sunday, and how any new snow is sticking to the newly formed rain crust which exists up to 2500m. There is still potential to trigger a deeper slab on the Oct. crust near the base of the snowpack.
Summary
Weather Forecast
Temperatures will cool off for Sunday with valley bottoms down to -10C and alpine temperatures reaching -15C. Winds will be moderate to strong in the alpine and variable starting as East in the AM switching to W/NW in the afternoon. Forecasts are currently calling for 5-15cm ending tomorrow by midday. Another pulse of weather will arrive Tuesday.
Snowpack Summary
Rain to 2500m on Friday and cooler temperatures Saturday have started to form a crust today which is 1-5cm thick. The thin October crust and facets in the lower snowpack have been found up to about 2300m. Some wind slabs in the high alpine have still been observed. Treeline snow depths range from 50-70 cm deep (up to 110 cm in lee areas).
Avalanche Summary
Some smaller wind slabs in the alpine have been observed in the last 24 hours outside of the sunshine ski area boundary. Also one planned ski cut in bounds at treeline which likely stepped down to the October rain crust. No other observations reported today.
Confidence
Due to the number and quality of field observations
Problems
Wind Slabs
New and old wind slabs will be susceptible to triggering in the high alpine over the short term. Variable wind directions mean these could be on many aspects.
- Be careful with wind loaded pockets, especially in steep confined alpine terrain.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
A thin crust formed in Oct. with facets exists in the lower snowpack. This has produced a few skier accidentals this week. A new rain crust up to 2500m on all aspects will likely decrease the likelihood of triggering but was still active today.
- Remote triggering is possible, watch out for adjacent slopes.
- Convex features and steep unsupported slopes will be most prone to triggering.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 10th, 2019 4:00PM