Avalanche Forecast
Issued: Feb 21st, 2021 4:53PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Storm Slabs and Loose Dry.
William Lawson,
Extreme winds, new snow and warm temperatures are promoting a HIGH danger rating. Avoid all avalanche terrain Monday.
Summary
Weather Forecast
Strong winds warm temperatures and moderate precipitation will continue Monday. As the system tapers early Tuesday morning, temperatures will begin to cool and upper elevation winds will subside.
Snowpack Summary
Strong to extreme SW winds, warm temps and new snow are creating wind slabs and storm slabs over the old faceted surface. We suspect this new storm snow/facet interface to be reactive. Below the newly formed instabilities the Jan 27 facet / sun crust persistent layer exist at tree line.
Avalanche Summary
Extensive loose dry avalanche activity to size 1.5 was observed throughout the forecast region Saturday. Though no slab avalanches were observed we suspect an increase in wind slab activity at tree line and above.
Confidence
Problems
Wind Slabs
Extreme winds continue to develop wind slab in the alpine and tree line. Much of this new load will be deposited over the old weak faceted surface.
- Use caution in lee areas. Recent wind loading has created wind slabs.
- Pay attention to overhead hazards like cornices which could trigger slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
New snow, intense winds and warm temperatures associated with the storm will promote slab development at all elevations as snowfall continues through Tuesday. Expect the new slabs to be touchy over the current faceted surfaces.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
- The new snow will require several days to settle and stabilize.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Dry
New snow and strong to extreme winds continue to produce extensive loose dry avalanche activity throughout the forecast region.
- Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 22nd, 2021 4:00PM
