Avalanche Forecast

Issued: Jan 17th, 2014 8:55AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs, Persistent Slabs and Deep Persistent Slabs.

bcorrigan, Avalanche Canada

Kootenay Boundary.

Daytime heating and solar radiation will play a large role in the danger rating for the next few days.

Summary

Confidence

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

Weather Forecast

Overnight: Temperatures will lower throughout the evening. Upper elevation winds should be light from the South west and below tree line winds should be light. Freezing level at valley bottom.Saturday: Sunny with some cloudy periods. Warm in the alpine with light westerly winds. Expect +5 degrees in the alpine with strong solar radiation. Freezing level to 2200 metres.Sunday: Southwest winds with a bit of cloud cover and cooler temperatures in the alpine. Freezing level down to about 1400 metres.Monday: Sunny, light Southwest winds and freezing levels to 1300 metres.

Avalanche Summary

No recent reports of avalanches in the K-B region, although neighboring regions are still reporting up to size 3 avalanches on E and SE slopes. We expect this to change significantly with the warming temperatures in the next few days.

Snowpack Summary

The North of the region received more storm snow over the past week than the rest of the region. The storm slab in the North is close to a metre thick and appears to be more touchy than in most of the rest of the region. The Rossland range has a shallower snowpack and weak basal facets continue to be a concern where wind slabs and storm slabs have added load above the weak layers. The forecast very warm alpine temperatures may result in a period of fairly rapid warming of wind and storm slabs above loose weak layers. Periods of strong solar radiation may cause moist or wet loose snow avalanches and/or cornice falls which may result in large additional loads above deeply buried weak layers.

Problems

Wind Slabs

Recent storm snow and strong winds has produced wind slabs at higher elevations. In some areas up to one metre thick. Warm alpine temperatures may result in loose wet avalanches on southerly aspects, or cornice falls, triggering deeper instabilities.

Be aware of the potential for wide propagations due to the presence of hard windslabs.>Be cautious as you transition into wind affected terrain.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

Recent storm snow may not be bonding to the surface hoar and melt-freeze crusts that developed before the storm. Storm slabs are more likely in areas sheltered from the recent strong winds. Forecast warm temperatures may result in easier triggering..

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar, facet/crust and depth hoar.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 5

Deep Persistent Slabs

This problem is more likely in areas that had a shallow snowpack during the cold arctic outbreak. Loose wet avalanches or cornice falls may trigger deeply buried weak layers resulting in large destructive avalanches..

Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Jan 18th, 2014 2:00PM