Archived

Avalanche Forecast

Mar 25th, 2016–Mar 26th, 2016

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Kootenay Boundary.

The kiss of the sun can spark avalanche activity. Plan your route to avoid exposure to sun-baked slopes.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

A ridge brings mixed sun and cloud for the weekend. The freezing level is around 1700 m. A front is expected to pass through late on Sunday/ Monday morning, bringing light snow with the freezing level around 1400 m.

Avalanche Summary

A handful of size 1-2 storm slabs were triggered by skiers, naturally and with explosives on Thursday. These were almost all on NW-NE aspects and above 1900 m. The kiss of the sun may spark a loose wet avalanche cycle, or make the storm slab more reactive.

Snowpack Summary

Cornices are large and looming in some areas. Recently formed melt freeze/ sun crusts are now buried by storm slabs and variable wind slabs. Several crusts are buried in the upper snowpack. The late February persistent weak layer down 70 to 120 cm remains a lingering concern. Test results are variable, with occasional sudden planar (pop) results. This interface may remain more reactive on northerly (shaded) aspects above about 1700 m, where buried surface hoar has the best chance of preservation. On sunny aspects, this interface may be a crust/ facet layer. While becoming unlikely, it could be triggered by a cornice fall or from a thin snowpack area.

Avalanche Problems

Storm Slabs

Recent storm snow has been redistributed by variable winds into slabs on many features at alpine and treeline elevations. The sun may make storm slabs more reactive on sunny aspects, or cause loose wet avalanches.

Be cautious as you transition into wind affected terrain.>Choose well supported terrain without convexities.>Minimize exposure to sun exposed slopes when the solar radiation is strong.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

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.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4