Avalanche Forecast

Issued: Feb 19th, 2017 4:49PM

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

mgrist, Avalanche Canada

South Columbia.

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 - The weather pattern is stable

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 (5-15cm), light winds and freezing levels around 1300 m.WEDNESDAY: Cloudy with light flurries (5-10cm), light southerly winds and freezing levels around 1100 m.

Avalanche Summary

A couple of skier-triggered wind slab avalanches (to Size 1.5) were reported on steeper (38 degree) north or northwest aspect slopes near 2100m on Saturday. There was also a natural wind slab (Size 2.0) reported on a steep easterly feature near ridge crest at 2200m in the Monashees. Wind slabs at higher elevations are 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 more recent snow bonding slowly to buried surface hoar and/or a crust, and blown into touchy wind slabs at higher elevations. Below 1500m a frozen rain crust is mostly supportive, but up to 1800m it can be breakable. 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. The mid and lower snowpack are generally well settled and stable in deeper snowpack areas but may be faceted and weaker in shallower areas.

Problems

Wind Slabs

Wind slabs are likely still lurking below ridge crests and behind terrain features at higher elevations. Choose your line carefully and use ridges or ribs to avoid pockets of wind slab.

Use caution in lee areas. Recent wind loading have created wind slabs.The recent snow may now be hiding windslabs that were easily visible before the snow fell.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

A persistent weakness down 50-80 cm remains remains sensitive to light triggers in isolated areas. Smaller avalanches have the potential to step down to this layer.

Be aware of the potential for large avalanches due to the presence of 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

2 - 3

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