Avalanche Bulletin - Sea to Sky

Avalanche Bulletin - Sea to Sky

Date Issued:

Valid Until:

Forecaster:shorton

Watch for heightened avalanche conditions as you climb to elevations where recent snow has accumulated. 

Tue, 26 AprWed, 27 AprThu, 28 Apr
Alpine2 Moderate2 Moderate2 Moderate
Treeline2 Moderate1 Low1 Low
Below Treeline1 Low1 Low1 Low
Confidence: Moderate
  • Uncertainty is due to the limited number of field observations.

Travel and Terrain Advice

  • Make observations and assess conditions continually as you travel.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Wind Slab

Unsettled weather between Sunday and Tuesday will deliver 20 to 40 cm of snow at upper elevations. This will leave the potential for wind slab avalanches on north and west facing slopes.

Cornice

Cornices may be weak and reactive to human triggers. They create a significant falling hazard, and can produce large slab avalanches as they fall onto the slope below.

Cornice failures are more likely during hot and sunny weather.

Wet Loose

Periods of sun could trigger wet loose avalanches in steep terrain.

Forecast Details

Avalanche Summary

Preliminary reports from Monday indicate there were several small (size 1) natural wind slab avalanches and a few small cornice falls. These wind slabs and cornices will be the main concern over the next few days.

Reports from the weekend include a few large cornice falls (such as the one in this MIN report near Brandywine that also triggered a very large slab avalanche in the steep terrain below), and a few small (size 1) human-triggered wind slab avalanches (such as the one in this MIN report on a north aspect east of Whistler).

Snowpack Summary

Winter conditions persist at treeline and above after Sunday night's storm delivered 15 to 30 cm of snow with strong south wind. We expect wind slabs from this storm to linger for a few days on steep lee slopes. This snow likely sits above dry snow on north-facing slopes above 2000 m, and then moist and crusty layers in all other areas. The lower snowpack should be strong under the current cool weather, but there are a few deeply buried crust layers to monitor once the weather shifts to warmer spring-like conditions.

Weather Forecast

MONDAY NIGHT: Mostly cloudy, no significant precipitation, light wind from the south, treeline temperatures drop to -7 C.

TUESDAY: Mostly cloudy, scattered flurries with 5-10 cm of snow above 1000 m, light wind from the south, treeline temperatures reach -5 C.

WEDNESDAY: Mix of sun and cloud, isolated flurries with up to 5 cm of snow above 1200 m, light wind from the southwest, treeline temperatures around -5 C.

THURSDAY: Mostly sunny, no precipitation, light wind, treeline temperatures around -2 C.

Source: avalanche.ca

Avalanche Bulletin - Sea to Sky