Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
South Rockies.
This bulletin was published with very little field data. If you've been in the mountains, we'd love to hear from you. Observations can be sent to [email protected].
Confidence
Poor - Due to the number and quality of field observations
Weather Forecast
On Monday and Tuesday a dry upper ridge will bring mainly sunny skies, light northwest winds and freezing levels around valley bottom. Overnight Tuesday and Wednesday, expect increased cloud and light snowfall as a pacific system moves eastward into the region. With this system we can expect 5-15cm of snow, strong westerly winds and freezing levels at about 1100m.
Avalanche Summary
Explosives control produced a few size 1 and 2 wind slab avalanches on Sunday. If you have any avalanche observations to report, please send an email to [email protected].
Snowpack Summary
Generally light amounts of snow have fallen in the last few days. In the alpine, winds have been conducive to blowing this snow into thin wind slabs in exposed lee areas. Below the recent storm snow you may find a layer of surface hoar. Below this, about 20cm of settled snow overlies a thick hard supportive rain crust that extends from the valley to alpine elevations. The crust is effectively bridging triggers from penetrating to deeper persistent weaknesses that formed earlier in the season. However, on high alpine slopes above the recent rain line poorly bonded crusts, facets, and/or buried surface hoar may be susceptible to triggers. Professionals are still concerned with a buried crust from November, down 50-70 cm, that could be triggered by large loads.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.