Avalanche Forecast

Issued: Apr 2nd, 2016 8:32AM

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.

Choose your route to avoid exposure to sun-baked terrain and slopes overhung by cornices.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Sunday

Weather Forecast

Sunday is expected to remain warm, with the freezing level around 2400 m. Clouds and isolated convective showers are possible. Â A front passing through on Monday is expected to bring around 10-20 mm precipitation and moderate SW winds, with the freezing level falling from around 2500 m to 1500 m. Cloud and a few snow showers may linger on Tuesday.

Avalanche Summary

A natural cycle of size 1-2 loose wet avalanches appeared to slow down on Friday, but an explosives control mission near Nelson produced several size 2-3 wet slab avalanches.

Snowpack Summary

Large cornices overhang alpine slopes and threaten to trigger avalanches on slopes below. These are likely to be fragile due to the warm weather. The snow surface is moist up to at least 2000 m on all aspects and may still be dry on shady aspects at higher elevations. At low elevations, the snowpack is isothermal. 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. A cornice fall could trigger a large avalanche on the slope 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.

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

Unlikely

Expected Size

3 - 6

Valid until: Apr 3rd, 2016 2:00PM