Avalanche Forecast

Issued: Feb 20th, 2017 3:47PM

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.

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 700 m.WEDNESDAY: Cloudy with light flurries / Light northerly winds / Freezing levels around 400 m. THURSDAY: Cloudy with sunny breaks / Light southerly winds / Freezing levels at valley bottom.

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 have 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 the weekend with only about 5-10cm new snow in most areas (20cm of low density snow near Blue River). Expect to find 15-25 cm of more recent snow blown into deep wind slabs at higher elevations. Lower down 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 and includes a sun crust on steep sun-exposed slopes, faceted snow, as well as surface hoar on sheltered open slopes. 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.

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

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.

Be aware of the potential for large, deep 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 - 4

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