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Avalanche Forecast

Feb 26th, 2017–Feb 27th, 2017
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
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
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
1: Low
The avalanche danger rating below treeline will be low

Regions: South Rockies.

While wind sheltered features should offer great riding, be very cautious if you poke out into wind exposed terrain. Fresh sensitive wind slabs are expected to continue to form as winds pick up over the next few days.

Confidence

Moderate - Wind speed and direction is uncertain on Wednesday

Weather Forecast

Light snowfall, cool temperatures and moderate westerly winds are expected for the first half of the workweek. There is potential for a significant warm up on Thursday. Stay tuned for details.MONDAY: Broken cloud cover, freezing level at valley bottom, light to moderate southwest wind, isolated snow flurries, 1 to 5 cm possible. TUESDAY: Broken cloud cover, freezing level at valley bottom, light to moderate west wind, 2 to 10 cm of snow possible.WEDNESDAY: Scattered cloud cover, freezing level at valley bottom, strong to extreme west/northwest wind, isolated snow flurries, 1 to 5 cm possible.Visit avalanche.ca/weather for a more detailed mountain weather forecast.

Avalanche Summary

On Saturday, two small size 1 wind slabs were triggered by skiers. Some loose dry avalanches to size 1.5 were observed on Friday in the Elk Valley North, near Crown Mountain. The deep persistent slab problem is a low probability/high consequence scenario that warrants extra caution around large open slopes, especially in shallow snowpack areas. There was a report on Tuesday of a size 3.5 avalanche at Mt Hosmer in the Lizard/Flathead region that released on or stepped down to the deep weak layer near the ground. On Wednesday we had a report from the Lizard range of another size 3.0 deep persistent avalanche on a northeast aspect in the alpine. Avalanche activity on Wednesday near Elkford was limited to loose snow up to size 1.5.

Snowpack Summary

On Saturday night the region picked up 2 to 20 cm, with the Castle area being the clear winner. This storm snow rests upon last weeks ageing storm slab. The mid-pack in this region is well settled, but the bottom third of the snowpack is composed of weak facets. Recent snow profile tests have produced failures with moderate input that released suddenly down 75 cm on the facetted crystals. In the Crowsnest North late last week up to 35 cm of recent storm snow lies above various old surfaces. Near Elkford up to 20 cm of old storm snow sits above a melt/freeze crust. Approximately 100-120 cm of settled snow sits above the weak layer of sugary facets that developed during the cold spell in December. Snow profile tests indicate hard shears in this location where the facets are sitting on a hard wind crust.

Avalanche Problems

Deep Persistent Slabs

A weak layer near the base of the snowpack has the potential for large avalanches, especially in areas with minimal rider compaction or thin variable snow cover.
Avoid steep convexities or areas with a thin or variable snowpack.Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 4

Wind Slabs

Recent storm snow may remain loose and unconsolidated in some areas, but human triggerable slabs are possible in areas where the storm snow has been transported by the wind, or settled into a slab.
Use ridges or ribs to avoid pockets of wind loaded snow.Be alert to conditions that change with elevation.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2