Avalanche Forecast

Issued: Feb 19th, 2017 5:06PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Persistent Slabs.

mgrist, Avalanche Canada

Purcells.

The best riding right now is probably on high north aspects, which is also where the hazard is the highest. Don't let your guard down when searching for fresh powder.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

We're into a fairly stable weather pattern: seasonal temperatures and isolated flurries.MONDAY: Cloudy with light flurries, local accumulations to 5cm, light to moderate southwesterly winds and freezing levels around 1400 m.TUESDAY: A mix of sun and cloud with light snow flurries starting in the afternoon (5-10cm), light winds and freezing levels around 1100 m.WEDNESDAY: Cloudy with light flurries (5-10cm), light southerly winds and freezing levels around 700 m.

Avalanche Summary

No new avalanches reported in the past 24 hours. Storm slabs from recent snowfall remain sensitive to light triggers and have the potential to step down and trigger persistent slab avalanches.

Snowpack Summary

We've had minor snowfall amounts (5-15cm) over the weekend with light winds. Expect to find 25-40 cm of fresh snow bonding slowly to buried surface hoar and/or a crust, and blown into deep wind slabs at higher elevations. At 2000m and below a melt-freeze crust can be found on almost all elevations and aspects. Storm snow from last week is still bonding poorly to the previous snow surface from early February, which is now down 60-80 cm and includes a sun crust on steep sun-exposed slopes, faceted snow, as well as surface hoar on sheltered open slopes. A persistent weakness buried mid January is now down 80-150 cm and the November crust is down around 200 cm.

Problems

Storm Slabs

The fresh snow is sensitive to light triggers and particularly deep and touchy on wind-loaded slopes.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Avoid freshly wind loaded features.Be alert to conditions that change with elevation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

A persistent weakness down 60-80 cm remains remains sensitive to light triggers in isolated areas. Smaller avalanches have the potential to step down to this and deeper persistent weakness resulting very large avalanches.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Whumpfing, shooting cracks and recent avalanches are all strong indicators of unstable snowpack.Be aware of the potential for large avalanches due to the presence of deeply buried weak layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 4

Valid until: Feb 20th, 2017 2:00PM