Avalanche Forecast

Issued: Mar 6th, 2018 3:50PM

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.

jsmith, Avalanche Canada

South Rockies.

The sun can pack a punch this time of year. Be aware of signs of deteriorating stability such as snow pin-wheeling down slopes or small point-release avalanching below cliffs.

Summary

Confidence

High -

Weather Forecast

WEDNESDAY: Mix of sun and cloud / Light to moderate southwesterly ridgetop winds / Alpine high of -7 with an above freezing layer of air between 1400-1600 m in some areas of the region.THURSDAY: Mostly cloudy / Light to moderate southwesterly ridgetop winds / Alpine high of -4 with an above freezing layer of air between 1100-1600 m in some areas of the region.FRIDAY: Mix of sun and cloud / Light westerly ridgetop winds / Freezing level rising to around 1600m.

Avalanche Summary

No new avalanches have been reported in this region.

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 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

Wind slabs are becoming less likely to human trigger. Steep, convex, and rocky areas are the most likely spots to trigger these lingering winds slabs.

Watch for newly formed wind slabs as you transition into wind affected terrain.Be aware of the potential for wide propagations due to the presence of hard windslabs.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - 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

Expected Size

2 - 3.5

Valid until: Mar 7th, 2018 2:00PM