Avalanche Forecast
Issued: Dec 30th, 2020 8:03AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
ross campbell,
If we get the 10cm of new snow, and moderate wind; the hazard in the Alpine may rise to considerable.
Summary
Weather Forecast
A weak warm front draped over Rogers Pass bringing light precipitation (5-10cm) today and tonight. Freezing levels will remain near valley bottoms. Mountain top winds could reach moderate. The front will also slowly fizzle out tonight. Flurries tomorrow with the FL rising to 1100m, and light SW winds. Friday through the weekend is looking STORMY!
Snowpack Summary
Approximately 25cm of new snow has fallen over the last few days, burying another surface hoar layer. Reports that the new snow is relatively right side up, with isolated storm slabs that are stubborn to trigger. This interface will become touchy in the coming days as it gets overloaded with storm snow and warm temperatures.
Avalanche Summary
There were MIN reports of skiers triggering loose dry avalanches up to size 2 in steep terrain, and one small storm slab in an immediate lee at treeline.
There was a natural size 2.5 storm slab from steep North facing terrain on Mt Macdonald.
Several very large avalanches last week failed on the early December crust, facet/surface hoar combo.
Confidence
Problems
Storm Slabs
Approximately 25cm of new snow has fallen over the last few days, burying another surface hoar layer in specific locations. The new snow will morph into a storm slab with the added load of new snow and warm temperatures in the coming days.
- Use safe ski cutting techniques to enter your line.
- Watch for stiffer feeling snow. Avoid areas that appear wind loaded.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The Dec 7th and Dec 13t layers produced very large avalanches last week, up to size 4! One of these very large avalanches, from a South aspect at Treeline, had the Dec 7th interface as the failure plane which consisted of a crust with facets above.
- Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.
- Be wary of large open slopes that did not previously avalanche.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 31st, 2020 8:00AM
