Avalanche Forecast

Issued: Dec 15th, 2020 8:08AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Storm Slabs, Loose Dry and Persistent Slabs.

ross campbell,

If the wind reaches forecasted values, our hazard will rise to CONSIDERABLE in the Alpine.

Summary

Weather Forecast

We're in store for an active weather week, with a series of fast moving storms set to move across BC.!

Today: 10cm new snow, mod-gusting strong wind from the SW, FL 900m

Tonight:10cm new snow, strong wind from the SW, FL 800m

Tomorrow: 5cm new snow, moderate wind from the SW, FL 1000m

Snowpack Summary

The lower and mid snowpack is relatively strong, with the Nov 5th Cr currently unreactive to stability tests or skiers. The upper snowpack is stitched together by multiple surface hoar layers, including another one buried on DEC13th. New snow is slowly building a slab over the aforementioned SH layer, and could become reactive today, or tomorrow.

Avalanche Summary

No new avalanches were observed from the HWY corridor yesterday. MIN reports of a natural cornice fall triggering a size 2.5 off of Mt. Bonney, and a Skier Controlled size 1.5 on Lookout Couloir. Ongoing reports of sluffing in steep terrain, primarily on solar aspects where a firm bed surface exists.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Storm Slabs

An icon showing Storm Slabs

10-15cm of new snow has buried another surface hoar layer (The Dec 13th). A storm slab may ripen over this interface today or tomorrow, as new snow continues to fall, coupled with mod-strong wind and moderate temperatures.

  • Convex features and steep unsupported slopes will be most prone to triggering.
  • Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Dry

An icon showing Loose Dry

Sluffing continues to be a concern with incremental loading of light new snow over a firm bed surface. Loose dry avalanches will have enough mass to push riders around in steep terrain. Extra care is required around cliffs and confined gullies.

  • Be aware of party members below you that may be exposed to your sluffs.
  • Avoid travelling on ledges and cliffs where sluffing may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

40cm sits on the Dec 7th weak interface of rain crust/sun crust/surface hoar combo. Our developing storm slab will test this layer in the coming days.

  • Caution on open slopes and convex rolls at treeline and below, buried surface hoar may be preserved.
  • Persistent slabs may be more sensitive to human triggering on solar asp where it sits on sun crust

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Valid until: Dec 16th, 2020 8:00AM