Avalanche Forecast

Moderate -

SUNDAY NIGHT: Clear with cloudy periods, light northwest wind, alpine temperatures drop to -18 C.MONDAY: Mix of sun and cloud, moderate northwest wind, alpine high temperatures around -14 C.TUESDAY: Cloudy with some isolated flurries, trace accumulations, light to moderate northwest wind, alpine high temperatures around -12 C.WEDNESDAY: Mostly cloudy with some isolated flurries, light north wind, alpine high temperatures around -12 C.

Preliminary reports from Sunday suggest wind slabs were reactive to human triggering in the alpine as indicated in these MIN reports (here and here).Several notable skier triggered avalanches were reported on Saturday. These included size 1-2 storm slab, wind slab, and persistent slab avalanches on all aspects at treeline elevations. Some were old buried wind slabs while others were new snow reacting above recently buried weak layers and crusts. Natural loose dry avalanches were also observed in steep terrain.On Friday, several size 1 slab avalanches were triggered, predominately on northeast aspects. In the south part of the region, numerous size 1-2 wind slab, storm slab, and persistent slab avalanches were reported every day between Tuesday and Friday (see this MIN report for examples).

Northerly winds are forming wind deposits in exposed areas, while sun crusts may be forming on south-facing slopes. 15 to 40 cm of low density snow has fallen since Tuesday, with greater amounts in the south of the region. This snow is gradually settling above a surface hoar and crust layer that was buried on February 7th and could eventually develop into a problem layer.Two additional weak layers of surface hoar have produced large avalanches in the region over the past month. A layer buried at the end of January is around 40 cm deep and a layer buried mid-January is between 50 and 90 cm deep. The mid-January layer may also be associated with a melt-freeze crust on southerly aspects. These layers are most prominent at treeline and below.The remainder of the snowpack is generally well-settled. However, there have been sporadic reports of very large avalanches that have released near the base of the snowpack. Most of the avalanches have been in the high alpine. There has been about one report a week for the past month.