Avalanche Forecast

Issued: Feb 28th, 2022 4:00PM

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

Chris Gooliaff,

Email

The timing and track of the incoming storm is uncertain.

Anticipate danger ratings to rise Tuesday, likely culminating in avalanche control with explosives tomorrow afternoon.

Summary

Weather Forecast

Conflicting weather models are uncertain with snowfall amounts/winds, but agree that a warming trend is here until Thurs

Tonight: Cloudy, Alp low -5*C, gusty strong SW winds

Tues: Flurries, 10cm, Alp high -3*C, FZL 1800m, mod/ gusty extreme SW winds

Wed: Sun and cloud, isolated flurries, Alp high -5*C, FZL 1500m, light to mod gusty SW winds

Snowpack Summary

25-30cm of storm snow overlies a facet layer, small surface hoar in sheltered areas Treeline and below, and a sun crust on steep solar aspects. The Feb 15 surface hoar/sun crust is down 50-80cm and has not been reactive in tests the last few days, but may re-awaken with the new load and warming temps.

Avalanche Summary

Several natural avalanches were detected in the hwy corridor off Mts Tupper and Macdonald early Monday morning.

A skier triggered sz 2 in the Connaught Path Sunday shows the new snow is not yet bonded to the underlying bed surface.

A field team in the Fidelity area was able to ski-cut short rolls and "pop" out small 20-30cm storm slabs.

Confidence

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

Problems

Storm Slabs

An icon showing Storm Slabs

As the snow accumulates and temperatures warm, expect the reactivity of the storm slabs to increase, especially where loaded by the moderate to strong SW winds. Currently there is plenty of new snow available for wind transport.

  • Use caution in lee areas in the alpine and treeline. Recent storm snow has formed slabs.
  • If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 3

Loose Dry

An icon showing Loose Dry

New snow covers surface hoar (2-4mm) near Treeline and below in sheltered areas, sun crust on steep solar aspects and a faceted interface everywhere else. Though likely to be small, it doesn't take a large slide to bury a person in a terrain trap.

  • Loose dry avalanches could trigger Storm Slab or Persistent Slab avalanches.
  • Be careful of loose dry power sluffing in steep, confined or exposed terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A persistent weak layer of surface hoar and/or sun crust sits 50-80cm down, depending on wind loading and aspect. As temps rise and snowload increases, this layer may become reactive in areas where it has not previously slid.

  • Persistent slabs may be more sensitive to human triggering on solar asp where they sit on sun crust
  • If triggered the storm slabs may step down to deeper layers resulting in larger avalanches.

Aspects: All aspects.

Elevations: Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Mar 1st, 2022 4:00PM

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