Avalanche Forecast

Issued: Feb 21st, 2017 3:00PM

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

mgrist, Avalanche Canada

Cariboos.

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. If the sun comes out in full force, use extra caution on south slopes.

Summary

Confidence

Moderate - The weather pattern is stable

Weather Forecast

We're into a stable and benign weather pattern with cooling temperatures and isolated flurries.WEDNESDAY: Cloudy with light flurries (local accumulations 5-15cm possible) / Light northerly winds / Freezing levels around 400 m.THURSDAY: Cloudy with sunny breaks and isolated flurries / Light southerly winds / Freezing levels at valley bottom / Alpine high temperatures near -8 Celsius.FRIDAY: A mix of sun and cloud and isolated flurries / Light variable winds / Freezing levels at valley bottom / Alpine high temperatures near -8 Celsius.

Avalanche Summary

On Friday there was a spooky remote-triggered Size 3 near Valemount. It was at ridge crest, upper treeline elevation on a southwest aspect. See here for this great MIN post.Since temperatures cooled down over the weekend, we've had limited reports of slab avalanches, even with cornice fall as a trigger.

Snowpack Summary

We've had little change over past several days with 1-5cm new snow each day in most areas (and some spots receiving 15cm low density snow). Expect to find 15-35 cm of newer snow blown into wind slabs at higher elevations, most recently by some moderate southeast winds. The sun is starting to pack a punch and can trigger loose snow avalanches mid-day. The sun is also creating a thin crust on steep southerly aspects. At lower elevations there's moist snow or supportive crust below 1700m. Settling snow (40-60cm) from last week is still bonding slowly to the previous snow surface from early February, which is now down 50-80 cm. The persistent weakness buried mid-January is now down around 80-100 cm and the surface hoar/facet weakness buried mid-December is down 100-150 cm. These deep persistent weaknesses still have the potential to wake up and become reactive with human triggers. (See MIN post above).

Problems

Wind Slabs

Touchy wind slabs have been found lurking below ridge crests and behind terrain features at higher elevations.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use ridges or ribs to avoid pockets of wind loaded snow.Avoid recently wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

A persistent weakness down 40-70 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, deep avalanches due to the presence of buried weak layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Feb 22nd, 2017 2:00PM