Avalanche Forecast

Issued: Feb 15th, 2017 4:17PM

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

cam_c, Avalanche Canada

Cariboos.

Watch for conditions that change with elevation. Heavy rain at lower elevations means heavy snow up high.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

THURSDAY: 5-15 mm of precipitation with strong southerly winds and freezing levels around 2000 m.FRIDAY: Unsettled conditions with isolated flurries, moderate southwesterly winds and freezing levels dropping to 1400 m.SATURDAY: A mix of sun and cloud with flurries possible late in the day, light winds and freezing levels around 1000 m.

Avalanche Summary

Reports from Tuesday include continued natural loose wet avalanche activity up to Size 1 on steep sun exposed slopes, as well as a Size 2.5 natural cornice triggered persistent slab avalanche running on facets buried early February. Over the weekend, several rider triggered avalanches were reported on the MIN including a size 3 that resulted in a full burial. Click here more details (1). (2), and (3). Rain at lower elevations is expected to destabilize the upper snowpack resulting loose wet sluffing and potentially increasing the sensitivity of triggering persistent slab avalanches. In the alpine, touchy new wind slabs have the potential to step down and trigger persistent slab avalanches.

Snowpack Summary

Flurries have resulted in light amounts of fresh snow at higher elevations, while elsewhere the snow surface has become wet, loose and cohesionless on sun-exposed slopes and at lower elevations. Rapidly settling storm snow from last week is still bonding poorly to the previous snow surface from early February, which is now down 40-70 cm and includes a sun crust on steep sun-exposed slopes, faceted snow, as well as surface hoar on sheltered open slopes. Recent strong winds from the south and west had redistributed the recent storm snow in exposed terrain forming wind slabs. 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 have the potential to wake up and become reactive with the current warm temperatures.

Problems

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

Wind Slabs

Touchy fresh wind slabs are likely lurking below ridgecrests 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.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Wet

Loose wet sluffs are expected in steep terrain features at lower elevation. Although generally slow moving, they can easily take you for a ride and run significant distances. They also have the potential to trigger slabs on the slopes below.

Avoid avalanche terrain during periods of rain.If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.Use extra caution on slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 16th, 2017 2:00PM