Avalanche Forecast

Issued: Jan 13th, 2017 4:28PM

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

Avalanche Canada swerner, Avalanche Canada

Wind effect is the critical factor. The safest, best riding may be in lower elevation terrain sheltered from the wind.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

The weather pattern is changing as the recent dominating arctic airmass slowly shifts south allowing a more regular pattern of Pacific frontal systems in.Saturday/ Sunday/ Monday: Mix of sun and cloud with alpine temperatures near -6. Freezing levels 1100 m and ridgetop winds light from the West. Check out the full synopsis here: http://www.avalanche.ca/weather/forecast

Avalanche Summary

On Thursday, a natural size 2 wind slab avalanche was reported from an North aspect near 2500m. Explosive triggered cornice drops initiated numerous slab avalanches size 2.5 and one size 3 from the slopes below. They were initiated from NE-S aspects above 2500 m. The details of these larger avalanches did not state if they were persistent slabs or wind slabs. Regardless, the size and magnitude is very destructive. With winds switching directions, recently formed stiff wind slabs may still be reactive to human triggering on a variety of aspects.

Snowpack Summary

15-30 cm of recent snow has buried variable old snow surfaces. These surfaces consist of wind scoured or old wind slabs in exposed terrain, surface hoar in sheltered terrain, and widespread faceted (sugary) old snow. Recent moderate winds from a variety of directions has redistributed some of this new snow on leeward terrain, building reactive wind slabs. The layer of facets from mid-December is still reactive to snowpack tests in isolated areas but is generally considered to be dormant during this period of cold, dry conditions but its status may change as we head into a warmer, wetter period next week.

Problems

Wind Slabs

An icon showing Wind Slabs
Recently formed wind slabs may still be reactive to rider triggering. Wind direction has changed and wind slabs may exist on all aspects.
Use ridges or ribs to avoid pockets of wind loaded snow.Wind direction has changed recently. Watch for slabs on all aspects.Watch for signs of instability such as whumpfing, or cracking.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 14th, 2017 2:00PM