Avalanche Forecast

Issued: Apr 3rd, 2014 9:20AM

The alpine rating is considerable, the treeline rating is moderate, 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 on Friday

Weather Forecast

Overnight and Friday: Light snow starting overnight and continuing through the day. Expect 3-5 cm by morning and another 3-5 cm during the day. Moderate to strong Southwest winds should develop overnight. The freezing level should drop down to 1300 metres overnight and then rise up to about 1800 metres.Saturday: Freezing level dropping to 1300 metres overnight. Flurries or convective snow showers combined with moderate Southwest winds and freezing levels rising to 1800 metres. Moderate snow fall beginning in the evening.Sunday: Expect 5-10 cm by morning combined with moderate Southwest winds. Freezing levels rising to 2000 metres.

Avalanche Summary

No new avalanches reported.

Snowpack Summary

Forecast new snow and Southwest wind may result in a new storm slab. High freezing levels may limit crust recovery before the new snow arrives. There are a few crusts in the snowpack that we are following. The March 25th crust is now down about 20-30 cm buried below a well settled layer of recent snow. The March 10th crust is buried down 60-90 cm and is reported to be widespread across the region up to about 2000 metres elevation. The facet/crust persistent weakness buried at the beginning of February is now down 70 - 200cm, and has been highly variable in terms of reactivity. In areas where the strong and supportive crust exists, triggering this layer has become unlikely. Avalanches releasing on this deeply buried weak layer could be very large and destructive.

Problems

Storm Slabs

Forecast new snow and Southwest wind are expected to develop new storm slabs that may not bond to the old surface in areas where the crust re-freezes before the storm. Rain at lower elevations may result in loose wet slides.

Extra caution needed around cornices with current conditions.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

Avalanches releasing on the deeply buried weak layer from early February are still a concern. Strong solar radiation, cornice falls, new loading, or storm slab avalanches in motion are all possible 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 4th, 2014 2:00PM