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Avalanche Forecast

Mar 23rd, 2017–Mar 24th, 2017
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: South Rockies.

Avoid lingering in the runout of avalanche paths because wind loading and cornice falls could trigger large avalanches.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

FRIDAY: Increasing cloud and afternoon flurries with 2-4 cm, strong southwest wind, freezing level around 1600 m with alpine temperature around -3 C.SATURDAY: Light flurries easing off throughout the day, strong southwest wind, alpine temperature around -5 C.SUNDAY: Sunny, moderate southwest wind, alpine temperature around -8 C.

Avalanche Summary

No recent avalanches have been reported. Evidence of a large natural avalanche cycle during last week's storm has been reported around the Crowsnest Pass / Sparwood area as well as around Waterton (typically size 2.5 deep persistent slabs). A fresher size 3 avalanche in the Alexander Creek drainage was possibly triggered by a cornice fall on Sunday. Widespread natural activity in the neighboring Kananaskis region suggest conditions may be touchier north of Elkford.Looking ahead, the primary concern is the potential for large deep persistent slab avalanches triggered by natural triggers such as a cornice fall. See the forecaster blog for advice on managing a low probability - high consequence problem (here) and the accompanying photos (here).

Snowpack Summary

Light precipitation has delivered 5-10 cm of heavy snow at higher elevations, while rain soaked has the snow below about 2000 m. Recent rain and sun have left a variety of crusts that are thicker and most supportive in open south facing terrain. Below the new snow and crusts, roughly 50-90 cm of snow sits above the February crust and facet interfaces. In some areas there may still be a poor bond to these interfaces. The bottom third of the snowpack is composed of weak facets and full-depth avalanches over this basal weakness remain a concern.

Avalanche Problems

Deep Persistent Slabs

Heavy triggers such as a cornice fall or wind loading are potential triggers for large avalanches on deep weak layers. Stay aware of overhead hazard when traveling at lower elevations.
Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Minimize exposure to sun exposed slopes when the solar radiation is strong.Recognize and avoid avalanche runout zones.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 4

Wind Slabs

Strong winds will be forming fresh wind slabs throughout the day in the lee of exposed terrain.
Use ridges or ribs to avoid pockets of wind loaded snow.If triggered, wind slabs may step down to deeper layers and result in large avalanches.Be alert to conditions that change with elevation and aspect.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2