Archived

Avalanche Forecast

Apr 2nd, 2013–Apr 3rd, 2013

Alpine

1: Low

The avalanche danger rating in the alpine will be low

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

1: Low

The avalanche danger rating in the alpine will be low

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

3: Considerable

The avalanche danger rating in the alpine will be considerable

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

Regions: Kootenay Boundary.

Be alert to conditions that change with daytime warming. Danger ratings are likely to exceed posted levels if solar radiation is strong, especially at treeline and below.

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Wednesday

Weather Forecast

Wednesday: A mix of sun and cloud / Light southwest winds / Freezing level at 2100mThursday: Moderate snowfall/rain developing late in the day / Moderate southwest winds / Freezing level at 2400mFriday: Moderate to locally heavy snowfall/rain / light to moderate southwest winds / Freezing level at 1700m

Avalanche Summary

Glide cracks are opening up and releasing. On Sunday a size 3.5 glide crack released on a West aspect at 2300 m and ran to valley bottom. Loose wet avalanches up to size 1.5 continue to be widespread.

Snowpack Summary

Large cornices loom over many slopes. The upper 10 cm of surface snow has become moist up to 2300 m, and melt-freeze conditions exist. Surface facetting and surface hoar (up to 12 mm) are prevalent on steep northerly aspects at upper elevations.The surface snow overlies an old crust (down 50-60 cm) which exists up to ridge top. The bonds with the crust have gained strength in most places, and some test results are showing resistant planar fracture characteristics. Having said that, the overlying slab could become reactive with daytime warming.

Avalanche Problems

Loose Wet

The extent of solar radiation on Wednesday is somewhat uncertain. If the sun is shining, loose wet avalanches will become likely on sun-exposed slopes. Wet slabs are also possible where an underlying crust exists.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Watch for wet loose or slab activity with forecast warm temperatures.>

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

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 4

Cornices

With solar radiation and daytime warming, large and potentially destructive cornices may become unstable.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Do not travel on slopes that are exposed to cornices overhead.>

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 5