Avalanche Forecast

Issued: Mar 5th, 2018 4:22PM

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

mbender, Avalanche Canada

South Rockies.

Although the temperature is forecast to remain cool at upper elevations, when the sun does come out it can have an immediate impact on those slopes directly facing it.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

TUESDAY: Mix of sun, cloud and isolated flurries / Light to moderate southwest wind / Alpine temperature -10WEDNESDAY: Mix of sun and cloud / Light southwest wind / Alpine temperature -9 THURSDAY: Mainly cloudy with scattered flurries / Light to moderate southwest wind / Alpine temperature -5

Avalanche Summary

Over the past week there have been reports of both natural and skier triggered loose dry avalanches in steep terrain to size 1.5.

Snowpack Summary

Accumulated storm snow from last week totals 25-40cm. This new snow covers previously wind-scoured, westerly slopes and old hard and soft wind slabs on leeward, easterly alpine and treeline slopes. Beneath these old wind slabs lies a well-settled mid-pack. The lower snowpack is generally weak with two primary concerns that are widespread:A widespread weak layer from mid-December composed of facets, crusts, and surface hoar that is 100-150 cm deep.A rain crust with sugary facets buried in late November near the bottom of the snowpack.

Problems

Wind Slabs

The recent new snow came in as fluff. There is now lots of new snow available to be transported into alpine and treeline lee terrain features with forecast west and southwest wind in the coming days.

Watch for newly formed wind slabs as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

Deeply buried weak layers are lingering near the base of the snowpack. These layers are most likely to be triggered from thin or variable snowpack areas or with a large load like a cornice fall.

Avoid steep convexities or areas with a thin or variable snowpackExtra caution needed around cornices with current conditions.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Mar 6th, 2018 2:00PM