Avalanche Forecast
Issued: Apr 28th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Wet Slabs, Cornices and Deep Persistent Slabs.
JH,
Avalanche Canada
If the elevated avalanche hazard doesn't deter you, hopefully the terrible travel conditions will.
It's a good time to tune up you bike, dust off your climbing shoes, or just dive into some spring cleaning.
Summary
Confidence
Avalanche Summary
Numerous loose snow and slab avalanches were observed on Friday, during the heat of the day. Avalanches were up to size 3 (significantly larger than in previous days) and are starting to gouge deeper into the snowpack. A deeper slab avalanche on the SW side of Cheops is suspected to have failed on the Mar. 31st crust.
Avalanches are expected to continue to increase in size as the snowpack warms.
Snowpack Summary
At upper elevations, warm temperatures and minimal overnight refreeze is weakening a moist upper snowpack. Several crusts buried in the top 50cm of the snowpack are beginning to break down as the snow warms. 20-40cm above the ground, the Nov 17 basal weakness can still be found in many areas.
Below treeline, the entire snowpack has become isothermal, and is losing strength as the day warms.
Weather Summary
Warm, sunny weather through the weekend, with above seasonal temps and high freezing levels (FZL).
Tonight: Clear, Alpine Low 7°C, FZL 3500m, Light S ridgetop wind.
Sat: Mainly sunny, Alpine High 12°C, Light SW wind, FZL 3600m.
Sun: Mixed sun and cloud, Low 9°C, High 15°C, FZL 3600m.
Mon: Isolated showers, Low 9°C, High 15°C, FZL 3700m.
Terrain and Travel Advice
- The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
- Avoid exposure to overhead avalanche terrain as temperatures increase.
Problems
Loose Wet
With intense solar heating and very little overnight refreeze the surface snow is moist and weak. Loose wet avalanches are easily triggered in steep terrain and can gain surprising mass.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wet Slabs
Several buried crusts exist in the upper snowpack, the deepest of which is the Mar 31 layer. As the upper snowpack loses strength and cohesion during this intense warm up these crusts may provide a failure plane for the wet snow.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
As temperatures soar to new highs expect cornices to become weak and begin failing naturally which may also trigger large avalanches on the slopes below. These features can be surprisingly large, give sharp ridge crests a wide birth.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The increasing warmth is penetrating deep into the snowpack. The potential for this early season basal weakness to wake up and produce very destructive avalanches increases with each day of warming.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Apr 29th, 2023 4:00PM
