Avalanche Forecast

The high pressure ridge is forecast to break down Sunday morning bringing light precipitation and lowering freezing levels followed by a classic diurnal melt-freeze cycle on Monday for the next couple of days.

Saturday night: Clear, moderate northwest wind, alpine low +3 C, freezing level 2800 m. 

Sunday: Mix of sun and cloud with isolated flurries, trace of new snow and rain below treeline, moderate to strong northerly wind, alpine high +4 C, freezing level dropping to 1900 m in the morning.

Monday: Mainly sunny, light to moderate north wind, alpine high +6 C, freezing level 2100 m.

Tuesday: Mainly sunny, light variable wind, alpine high +8 C, freezing level 2400 m.

On Friday numerous wet loose avalanches on all aspects and wet slabs to size 3 on solar aspects were reported. Numerous wet loose avalanches to size 2 and several wet slab avalanches of size 2.5-3 and one size 3.5 were observed on steep solar aspects on Thursday. 

A couple of recent natural cornice failures size 2.5 did not trigger slabs on slopes below except for one which triggered small slab avalanches.

Neighbouring Glacier National Park reported a few very large (size 3-4) glide slab releases last week. Glide slabs are hard to predict and can release at any time, so it is important to avoid slopes with glide cracks.

The snow surface consists of a melt-freeze crust on solar aspects and shaded aspects up to treeline which transitions into moist/wet snow during the day. Dry snow might still be found on northerly aspects in the alpine above 2000 m. 20-40 cm of recent snow has formed isolated pockets of wind slab on leeward slopes and behind terrain features. The recent snow sits on a series of melt-freeze crusts on all aspects below 1900 m and southerly aspects to mountain top. On North aspects in the alpine, the recent snow sits on dry wintery snow surfaces and possibly surface hoar on wind-sheltered slopes. 

Cornices are large, fragile and failing with warm temperatures. Several natural cornice falls were observed recently. 

Recent periods of warm weather are expected to have helped old persistent weak layers heal, including a few crusts buried over the last month as well as a facet layer 150 cm deep from the mid-February cold snap. 

• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
• Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
• Avoid sun exposed slopes, especially if snow surface is moist or wet.
• Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.