Avalanche Bulletin - Sea to Sky

Avalanche Bulletin - Sea to Sky

Date Issued:

Valid Until:

Forecaster:shorton

New snow could create dangerous avalanche conditions at higher elevations on Monday, be especially careful in wind-affected terrain.

Mon, 25 AprTue, 26 AprWed, 27 Apr
Alpine3 Considerable2 Moderate2 Moderate
Treeline2 Moderate2 Moderate1 Low
Below Treeline1 Low1 Low1 Low
Confidence: Moderate
  • Forecast snowfall amounts are uncertain.

Travel and Terrain Advice

  • Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
  • Dial back your terrain choices if you are seeing more than 20 cm of new snow.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Wind Slab

Expect reactive slabs to form as new snow accumulates on steep wind-affected slopes, especially in areas that receive more than 20 cm.

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.

Forecast Details

Avalanche Summary

Avalanche activity on Monday will be driven by the new snow.

A few slab avalanches were reported on Saturday including a small (size 1) human-triggered wind slab on a north aspect east of Whistler and a large (size 2.5) natural slab avalanche triggered by a cornice fall from the west side of Highway 99. There were also several small to large wet loose avalanches (size 1-2) on sun-exposed slopes. No reports from Sunday have been received at the time of publishing.

Snowpack Summary

By Monday afternoon there will be 15 to 30 cm of new snow above 1000 m, likely forming some reactive slabs in steep wind-affected terrain. As temperatures cool, this snow will sit above a crust layer in most areas except for north-facing slopes above 2000 m where dry snow was reported prior to the storm. The lower snowpack should be strong under the current cool weather, but large looming cornices remain a concern this time of year.

Weather Forecast

SUNDAY NIGHT: Cloudy with flurries brining 15-25 cm of snow above 1300 m, 40-60 km/h wind from the south, treeline temperatures around -3 C.

MONDAY: Unsettled weather with clouds and scattered flurries bringing another 5-15 cm of snow above 1000 m, 30-50 km/h wind from the southwest, treeline temperatures drop to -5 C.

TUESDAY: Mostly cloudy, isolated flurries with 5-10 cm of snow above 1000 m, 20 km/h wind from the southwest, treeline temperatures around -4 C.

WEDNESDAY: Mostly cloudy, isolated flurries with trace amounts of snow above 800 m, 20 km/h wind from the southwest, treeline temperatures around -5 C.

Source: avalanche.ca

Avalanche Bulletin - Sea to Sky