Avalanche Forecast

Issued: Apr 5th, 2014 9:20AM

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

triley, Avalanche Canada

Kootenay Boundary.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Overnight and Sunday: Freezing levels dropping overnight to about 1500 metres combined with moderate Southwest winds and light precipitation. Freezing levels rising up to 2300 metres with moderate Westerly winds during the day. Expect broken skies with sunny periods.Monday: Freezing levels are expected to continue to rise through the night and reach about 2600 metres during the day. Broken skies may result in periods of strong solar radiation to add more warmth to the snowpack.Tuesday: Southwest winds increasing to strong with cloudy skies and moderate to heavy precipitation beginning in the afternoon. Freezing levels remaining at 2600 metres overnight and then lowering slightly during the day.

Avalanche Summary

No new avalanches reported.

Snowpack Summary

Another 5-10 cm of new snow overnight has increased the recent storm slab to 10-30 cm in depth. The new thin storm slab is sitting on a 2-5 cm melt-freeze crust that developed over the past few days on all but shaded North aspects in the alpine. This crust has been reported to be "knife" resistance in some parts of the region and may have a layer of surface hoar below the new storm snow. There is now about 75 cm of well compacted snow above the March 10th melt-freeze crust. In some areas the March 10th crust is helping to bridge over the deeply buried late January/early February persistent weak layer. The Jan/Feb deep persistent weak layer continues to be a concern for very large destructive avalanches. Releases on this layer may be more likely during periods of strong solar radiation and/or prolonged warm temperatures at alpine elevations.

Problems

Storm Slabs

Another few cm are expected to add to the developing storm slab. Warm temperatures and strong solar radiation may settle the recent snow into a cohesive slab. This slab may not be well bonded to the old crust in some areas.

Extra caution needed around cornices with current conditions.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

The deeply buried weak layer of crusts and facets continues to be a concern for hard to predict very large avalanches. Warm temperatures, strong solar, or heavy loading from new snow or cornice falls are likely triggers.

Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Apr 6th, 2014 2:00PM