Avalanche Forecast
Issued: Mar 1st, 2019 4:50PM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems include Be mindful of the persistent slab problem lingering at lower elevations as you search for snow that has been sheltered from recent winds.
Summary
Confidence
High -
Weather Forecast
Friday night: Clear. Light northeast winds.Saturday: Sunny. Light northeast winds. Alpine high temperatures around -20.Sunday: Sunny. Light east winds. Alpine high temperatures around -16.Monday: Sunny. Light northeast winds. Alpine high temperatures around -13.
Avalanche Summary
No new avalanches were reported on Wednesday.Avalanche activity on the mid-January weak layer described in our snowpack summary has seen a steady decline, however snowpack tests continue to show strong potential for reactivity at this layer, especially below treeline. This shows persistent slab avalanches are still possible for a skier or rider to trigger in specific locations. The consequences for doing so remain high.
Snowpack Summary
Recent moderate to strong northerly ridgetop winds have created wind slabs on lee features at treeline and above. Below this wind affected layer, older buried wind slabs exist on a variety of aspects. These remain a concern for overlying facets (weak, sugary snow), causing them to remain reactive for longer than is typical for a wind slab problem.A weak layer that was buried in mid January is down 50-60 cm and is especially prominent below treeline. This layer consists of surface hoar (weak, feathery crystals) and facets, and may be combined with a crust on south facing slopes. Avalanche activity on this layer has been on the decline, but snowpack test results continue to indicate this layer may still be possible to human trigger in specific locations. It has been most reactive in sheltered openings at lower treeline elevations and below.The lower snowpack is generally considered to be strong, except for shallow, rocky areas where cold temperatures continue to facet (weaken) the snowpack.
Problems
Wind Slabs
Recently formed wind slabs can be found primarily on southwest aspects. Below them, hard, buried wind slabs on all aspects have continued to surprise riders. Thin to thick rocky areas are likely places to trigger these.
Steep and rocky terrain are likely places to trigger buried wind slabs.Avoid wind loaded pockets, especially near ridge crests and roll-overs.Avoid slopes that sound hollow or drum-like.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Approximately 50-60 cm of snow sits above a persistent weak layer of surface hoar (weak, feathery crystals) that was buried in mid-January. This layer is slow to change and has evolved into a low likelihood, high consequence avalanche problem.
Avoid low elevation cut-blocks where this layer is well preserved.Use conservative route selection, choose moderate angled terrain with low consequence.Avoid steep, open and/or sparsely treed slopes at and below treeline.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Mar 2nd, 2019 2:00PM