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Avalanche Forecast

Mar 27th, 2020–Mar 28th, 2020
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
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: South Rockies.

Steady winds continue to redistribute loose snow, the trend will continue as flurries accumulate through the weekend.

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

Friday night: Cloudy with isolated flurries, trace to 5 cm. Alpine low temperature -7 C. Moderate west wind. Freezing level 1500 m.

Saturday: Cloudy with scattered flurries, trace to 5 cm. Alpine high temperature -2 C. Moderate southwest wind. Freezing level 1700 m.

Sunday: Cloudy with scattered flurries, trace to 5 cm. Alpine high temperature -1 C. Moderate gusting to strong southwest wind. Freezing level 1800 m.

Monday: Flurries, 5-15 cm. Alpine high temperature -3 C. Moderate gusty southwest wind. Freezing level 1700 m and dropping.

Avalanche Summary

We have very limited field observations at this time. There have be no new avalanches reported in the region.

Snowpack Summary

15-25 cm recent snow is now wind affected and redistributed at treeline and above. A sun crust has formed on steep solar slopes and below treeline. Steady winds continue to impact loose surface snow. 

The recent new snow sits above a melt-freeze crust on sun-exposed slopes and on previously wind-affected snow in other areas, so new slabs may take some time to bond to these surfaces. A layer of faceted grains overly a melt-freeze crust from early February. This layer currently sits 40 to 80 cm below the surface. 

The base of the snowpack contains basal facets that are most prominent in shallow, rocky start zones.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Avalanche Problems

Wind Slabs

Steady southwest winds are redistributing new flurries and loose surface snow building new wind slabs on leeward slopes, particularly near ridgetops and crossloaded terrain features.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Deep Persistent Slabs

Weak snow at the bottom of the snowpack hasn't gone away. Evidence of deep persistent slab avalanches has been focused in the Sparwood-Elkford area over the past month. Human triggering is most likely around steep, rocky terrain features or anywhere the snowpack is thin and weak. A failing cornice could initiate a deep persistent slab when it impacts the slope below.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2.5 - 3.5