Avalanche Forecast

Issued: Apr 1st, 2013 9:46AM

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

swerner, Avalanche Canada

South Rockies.

Danger could INCREASE TO CONSIDERABLE with intense radiation on south and west aspects, especially at treeline and below. Be aware of how the warm weather is changing the snowpack.

Summary

Confidence

Good - Timing or intensity of solar radiation is uncertain

Weather Forecast

The weather pattern starts to change as the dominating upper ridge weakens allowing a more onshore flow, bringing cloudy skies and light precipitation.Tuesday: Mix of sun and clouds. Alpine temperatures near 2.0 and freezing levels riding to 2500 m. Ridgetop winds will blow light from the West.Wednesday/Thursday: Mainly cloudy with light precipitation amounts. Alpine temperatures near 2.0 and freezing levels around 2200 m. Ridgetop winds light from the West.

Avalanche Summary

On Monday, numerous wet slab avalanches and glide crack releases were reported up to size 3 from South-West aspects.

Snowpack Summary

We are in a classic spring melt-freeze cycle. The surface snow becomes moist up to 2200m on all aspect and to ridgecrest on south and west facing slopes. Large cornices looming cornices threaten many slopes below. Surface hoar growth and surface facetting is happening at night on high sheltered, northerly aspects. A buried rain crust can be found down 50 cm and exists up to around 2100 m. The bonds at the crust has shown variability though the region. It is important to dig down and test weak layers before dropping into your line. A large trigger such as a cornice fall or a skier/sledder hitting the sweet spot, could potentially trigger a large avalanche on this layer.

Problems

Loose Wet

Warmer temperatures and sunshine promotes deterioration within the upper snowpack. If surface snow becomes moist or wet, loose wet avalanches are likely. Watch solar aspects.

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

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Wet Slabs

Large wet slab, and glide crack releases have been widespread on South-West aspects.

Avoid traveling on solar slopes when the sun is out, especially if they have not previously avalanched.>

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 6

Cornices

Large looming cornices exist on most ridgelines. They are a hazard in themselves and they could trigger slopes below.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 5

Valid until: Apr 2nd, 2013 2:00PM