Avalanche Forecast
Issued: Apr 18th, 2019 4:15PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Dry and Loose Wet.
Tim Haggarty,
Parks Canada
An avalanche cycle is expected Friday. Warm temperatures and possibly rain will make for poor travel at low elevations while extreme winds and more snow will make for full winter conditions in the alpine. A good time to avoid avalanche terrain.
Summary
Weather Forecast
A significant cold front should cross the divide overnight Thursday. Temperatures ahead of the front have been rising with rain expected to 2000m. Winds will spike to extreme as the front passes and remain in the strong range Friday with up to 40cm falling above 2000m. Expect cooling and at least some clearing Saturday as the winds finally diminish
Snowpack Summary
Between 60-80 cm of snow has fallen in the last week with snowpack values reaching seasonal highs 2000m and above. Extreme west winds on Wed created widespread windslabs in alpine areas. Moderate winds Thursday continue to produce significant sluffing of loose snow. Expect crusts below 2000m to be weak with warm temps and possibly rain Friday.
Avalanche Summary
Winds Thursday continued to produce a widespread cycle of loose dry avalanches and likely a few slabs out of high alpine terrain along the divide while broken skies and warm temperatures produced minor loose wet activity at low elevations further to the east. A few large slabs were seen in high alpine areas Wednesday as a result of strong winds.
Confidence
Problems
Wind Slabs
The alpine has had snow piling up of the past week and when winds hit Wednesday, slabs up to 1m deep quickly formed and produced a natural cycle. Now with more snow and extreme winds forecast, further natural slab activity can be expected.
- Minimize overhead exposure during periods of heavy loading from new snow, wind.
- Avoid steep lee and cross-loaded slopes
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Loose Dry
Deep, loose dry snow exists at the high elevations and the wind is generating sluffs that are running down gullies and steep alpine faces. These sluffs can easily trigger wind slabs as they impact snow slopes below.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Warm temperatures overnight and the potential for rain will likely weaken surface crusts below 2000m Friday. Expect difficult travel conditions at best and be wary of the potential for avalanches on steep slopes if the crusts do break down.
- Use extra caution on slopes if the snow is moist or wet.
Aspects: South, South West, West.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Apr 19th, 2019 4:00PM
