Avalanche Forecast

Issued: Feb 20th, 2017 5:21PM

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.

Avalanche Canada mgrist, Avalanche Canada

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 stable and benign weather pattern: cooling temperatures and isolated flurries.TUESDAY: A mix of sun and cloud / Light snow flurries starting in the afternoon (5-10cm) / Light to moderate southwesterly winds / Freezing levels around 1400 m.WEDNESDAY: Cloudy with flurriesĀ  (5-15cm) / Light southwesterly winds / Freezing levels around 700 m. THURSDAY: Cloudy with sunny breaks and isolated flurries / Light northerly winds / Freezing levels around 200 m.

Avalanche Summary

On Monday afternoon we had three separate large avalanches: one natural and two triggered by humans:1) A Size 3 persistent slab (50-120cm thick) near Golden was remote triggered by a touring party on a southeast aspect near 2300m.2) A Size 2.5 persistent slab (40-75cm thick) near Golden was triggered by a skier on a northeast aspect near 2300m.3) A Size 2.5 persistent slab (30cm thick) near Invermere ran naturally on a north aspect near 2600m. 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 (5-20cm) over the weekend with moderate southeasterly winds in some locations. Expect to find 25-40 cm of fresh snow bonding slowly to buried surface hoar and/or a sun 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

An icon showing Storm Slabs
The fresh snow is sensitive to light triggers and particularly deep and touchy on wind-loaded slopes.
Be alert to conditions that change with elevation.Avoid freshly wind loaded features.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs
A persistent weakness down 60-80 cm 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.
Be aware of the potential for large avalanches due to the presence of deeply buried weak layers.Whumpfing, shooting cracks and recent avalanches are all strong indicators of unstable snowpack.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 4

Valid until: Feb 21st, 2017 2:00PM