Avalanche Forecast

Issued: Mar 16th, 2017 5:19PM

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

Avalanche Canada mbender, Avalanche Canada

A momentary reprieve from the precipitation and high freezing levels on Friday. Yet we still have dangerous avalanche conditions. Saturday it will start all over with precipitation and warm temperatures forecast again.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Saturday

Weather Forecast

FRIDAY: Scattered flurries / Moderate south wind / Alpine temperature -6 / Freezing level 1400mSATURDAY: Snow, accumulation 25-35cm / Moderate to strong southwest wind / Alpine temperature -3 / Freezing level 1900mSUNDAY: Broken skies with isolated flurries / moderate west wind / Alpine temperature -13 / Freezing level 800mMore details can be found on the Mountain Weather Forecast.

Avalanche Summary

The past few days warm and wet weather have seen a natural avalanche cycle to size 2.5 from a variety of aspects and elevations. In the coming days expect the likelihood of triggering an avalanche to remain elevated.

Snowpack Summary

Around 60-90cm of new snow has fallen at upper elevations over the past several days and has been redistributed by moderate southerly wind. Warm temperatures on Sunday through Tuesday has resulted in moist and/or rain saturated snow on all aspects up to 2100m. The new snow sits on top of faceted snow as well as isolated small surface hoar in sheltered areas and a thin sun crust on steep southerly aspects. The persistent weakness buried late-February is now down 90-140cm, and is composed of weak facetted crystals on a thick rain crust as high as about 2000m and facets on sun crust on steep southerly aspects. This layer has produced easy results in recent snowpack tests and has proven especially reactive on steep southerly aspects. Several deeper persistent weaknesses also remain a concern, including surface hoar buried early-February and mid-January (primarily in the northern Purcells). The november crust and basal facets are still reactive in shallow, rocky start zones.

Problems

Storm Slabs

An icon showing Storm Slabs
The recent storm snow is still susceptible to human triggering. These storm slabs are particularly deep and touchy on slopes loaded by southerly winds.
If triggered, storm slabs may step down to deeper layers resulting in large avalanches.Be cautious as you transition into wind affected terrain.Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Persistent Slabs

An icon showing Persistent Slabs
Various persistent weaknesses strewn throughout the snowpack create the potential for large step-down avalanches. Heavy loads such as a smaller storm/wind slab avalanche or a cornice fall increase the likelihood of triggering these layers.
Avoid steep convexities or areas with a thin or variable snowpack.Be aware of the potential for large avalanches due to the presence of deeply buried weak layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Loose Wet

An icon showing Loose Wet
As temperatures slowly cool there may still be the lingering possibility of triggering loose wet avalanches that step down to deeper weak layers.
Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 17th, 2017 2:00PM