Avalanche Forecast

Issued: Nov 23rd, 2018 5:07PM

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

Avalanche Canada cgarritty, Avalanche Canada

Friday was an active day for avalanches. Gather information to supplement this forecast as you travel and be especially tuned in to signs of instability.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Friday night: Mainly cloudy with isolated flurries and a possible trace of new snow. Light north winds.Saturday: A mix of sun and cloud. Light northwest winds. Alpine high temperatures of -7.Sunday: A mix of sun and cloud. Light southwest winds. Alpine high temperatures of -4.Monday: Mainly cloudy with isolated, increasingly wet flurries as freezing levels rise to 2500 metres. Strong southwest winds and alpine high temperatures reaching 0.

Avalanche Summary

Preliminary reports since Friday's new snow show a natural avalanche cycle during the Friday overnight period as well as explosives control in the Fernie area producing storm slab releases to size 2. Visibility of the extent of avalanche activity remained limited on Friday.

Snowpack Summary

Moderate to heavy snowfall over Thursday and Friday brought about 30 cm of new snow to the region. This new snow has now buried a recently formed layer of weak, feathery surface hoar previously found on the snow surface.  Below this layer of surface hoar, the new snow has also buried pockets of recently reactive wind slab in wind-exposed alpine and treeline terrain. This wind-affected layer sits above a complex of late-October and early-November melt-freeze crusts and facets. The snowpack is deepest at alpine and treeline elevations, where you might now expect to find total depths of around 70 cm. These depths taper rapidly with decreasing elevation.

Problems

Storm Slabs

An icon showing Storm Slabs
Heavy snowfall led to heightened natural avalanche activity on Friday. Expect the potential for human triggered storm slabs to persist as natural avalanching tapers off.
Watch for signs of instability, such as whumphing, shooting cracks, and recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Nov 24th, 2018 5:07PM