Avalanche Forecast

Issued: Mar 31st, 2016 8:54AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Loose Wet, Cornices and Persistent Slabs.

pgoddard, Avalanche Canada

Kootenay Boundary.

A Special Public Avalanche Warning is in effect due to intense warming.

Summary

Weather Forecast

Hot weather continues through the weekend, with the freezing level around 2800 m. A brief disturbance on Saturday may bring some cloud, increasing westerly winds, and localised convective showers.

Avalanche Summary

A natural cycle of size 1-2 loose wet and wet slab avalanches continued on Thursday. Similar activity is expected until temperatures cool.

Snowpack Summary

On shaded slopes above 2000 m you may still find cold winter snow (and unicorns), which is reported to be settled and faceted on sheltered slopes, and wind-affected in exposed areas. Warm temperatures have promoted a daily melt-freeze cycle on all other snow surfaces. Cornices are large and looming and have become increasingly weak with the sunny weather. In the upper snowpack you'll likely find a few hard crusts which exist everywhere except on high, north-facing terrain. The late February surface hoar/ crust interface (down 80 to 130 cm) remains a low probability/ high consequence concern. Test results are variable, with occasional sudden planar (pop) results. While generally becoming unlikely to trigger, this layer could produce surprisingly large and destructive avalanches with a cornice fall or warm temperatures.

Problems

Loose Wet

Loose wet avalanches are likely on all steep slopes, especially those getting baked by the sun. Wet slabs are possible too.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

Large fragile cornices threaten many slopes and could trigger large avalanches on slopes below.

Do not travel on slopes that are exposed to cornices overhead.>Give cornices a wide berth when travelling on ridges.>

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 5

Persistent Slabs

Persistent slabs may wake up with the prolonged warming, or be triggered by cornice fall.

Choose well supported terrain without convexities.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Minimize exposure to overhead avalanche terrain, as large avalanches may reach run out zones.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Apr 1st, 2016 2:00PM