Avalanche Forecast
Issued: Mar 19th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet and Persistent Slabs.
astclair,
Avalanche Canada
Warm sunny weather continues. Use increased caution when slopes and cornices warm up throughout the day. Deeper weak layers may still persist. Make observations and assess conditions continually as you travel.
Summary
Confidence
Weather Forecast
Thursday night: Decreasing cloud, light west wind, alpine temperature -9 C, freezing level valley bottom.
Friday: Mostly clear, light west wind, alpine temperature -4 C, freezing level 1700 m.
Saturday: Mix of sun and cloud, light west wind, alpine temperature -7 C, freezing level 1600 m.
Sunday: Increasing cloud, light west wind, alpine temperature -8 C, freezing level 1600 m.
Avalanche Summary
Over the past several days, avalanche activity was reported as natural loose wet avalanches (size 1-2) running in steep, sun-exposed terrain in the alpine. Cornices were also observed failing naturally, primarily on north, northeast, and east aspects.
In the last week, there have been multiple reports of large (size 2-3) natural, human-triggered, and explosive-triggered avalanches releasing on the late February surface hoar layer. These avalanches occurred on a variety of aspects between 1700 m and 2300 m and were breaking 40-100 cm deep.
The number of data sources for the region is diminishing as professional operations close. If you're spending time in the mountains, consider sharing your observations via the Mountain Information Network. Heightened diligence and conservative risk management is recommended at this time.
Snowpack Summary
On Wednesday, temperatures reached 0 C up to 2000 m with strong solar radiation. You can expect to find either moist surface snow or crust on sun-exposed slopes.
Snow from last week may sit on a weak surface hoar layer and a crust on steep solar aspects formed in early March. Moderate to strong northeast and east wind redistributed snow and formed wind slabs that may remain possible to trigger in isolated areas.
A widespread weak layer of surface hoar from late February is buried 60-120 cm deep. Though there is a low likelihood of triggering an avalanche on this layer, the consequences of doing so would be high. Read more about surface hoar on our forecaster blog.
Terrain and Travel
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.
- Be aware of the potential for large avalanches due to the presence of buried surface hoar.
- Make observations and assess conditions continually as you travel.
Problems
Loose Wet
Small loose dry or wet avalanches are possible in steep terrain facing the sun during the heat of the day. Cornices may also warm and weaken and could act as triggers for large slab avalanches.
Aspects: South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A weak layer of surface hoar is buried 60-120 cm deep and is still sensitive to triggering in specific areas. Although this problem can be found on all aspects and elevations, north to east aspects near treeline have been a hot-spot for reactivity.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 20th, 2020 5:00PM
