Avalanche Forecast
Issued: Mar 5th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
snow safety,
Cooler temperatures and less solar input Saturday should reduce the likelihood of triggering persistent slabs. However, its a big forecast region, and there is still uncertainty as to how reactive these will be in the different areas.
Summary
Weather Forecast
5-10cm (most up Hwy. 93N) overnight ending Saturday AM. Associated mod- strong winds will ease in the AM as well. 3000m temperatures around -15C and valley bottom highs around 0 to 5C.
Snowpack Summary
Its crust season. Expect these to be widespread at lower elevations. Previous strong SW winds scoured alpine ridges, creating wind slab in some alpine lees. 2 active persistent layers (Feb 19, Jan 27) of facets and /or suncrust are 30-80cm down on average. In thin areas, the basal depth hoar and crust is still a prominent layer in the snowpack.
Avalanche Summary
The last few days with warmer temperatures and increased sun have seen many avalanches to size 3 caused by explosives, skiers, and natural triggers. Most seem to be failing on one or both of the persistent layers.
Confidence
Problems
Persistent Slabs
Two layers of facets and/or sun crust in the top meter of the snowpack have been active in the past week. Surface crusts formed over the last 2 days may reduce the likelihood of triggering at lower elevations and on solar aspects.
- Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Some wind slabs exist in lees of alpine features from previous strong winds. We haven't seen much evidence of them being reactive over the last 24 hours. Cornice failures have also been noted in the past few days from recent loading.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 6th, 2021 4:00PM
