Another hot day with a limited overnight freeze keeps the avalanche danger elevated. Wet slab avalanches are large enough to affect all elevations running full path to the valley. Don't linger in runout zones and steer clear of cornices from above and below.
Summary
Confidence
Weather Forecast
Wednesday: A mix of sun and cloud. Alpine temperatures near +4 C and freezing levels 2500 m.
Thursday: A mix of sun and cloud. Ridgetop wind light from the northwest. Alpine temperatures near 0 C. Freezing levels 1600 m.
Friday: Mostly cloudy with some sun. Ridgetop winds light from the South. Alpine temperatures 0 C and freezing levels 1700 m.
Avalanche Summary
No recent avalanche reports on Tuesday.
On Monday, wets slabs and glide slabs up to size 3 were reported. Natural wet loose avalanche activity up to size 2 continues with these warm days.
Last weekend, widespread loose wet and cornice activity was still ongoing. The Coquihalla zone also saw glide slabs and wet slabs up to size 3.
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Snowpack Summary
A slight dip in overnight freezing levels combined with radiant cooling has formed a melt-freeze crust from 1700-2200 m. The crust will likely break down quickly (by noon) with solar radiation and freezing levels through the roof. At lower elevations and solar aspects, the snowpack is isothermal. Steep north aspects above 1800 m and higher may still hold dry wintery snow.
Cornices are large and looming along ridgelines. Sun and warm temperatures will increase the chances of cornice failures, especially when temperatures remain above zero overnight.
Terrain and Travel
- Avalanche hazard is expected to to increase througout the day, think carefully about your egress.
- Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Keep in mind that wet avalanches can be destructive due to their high density.
- Avoid lingering or regrouping in runout zones.
Problems
Wet Slabs
The likelihood of wet slab avalanches increases during prolonged periods of warm temperatures, as the heat penetrates deeper into the snowpack. These avalanches are dense, destructive, and can run far, reaching otherwise snow-free valley bottoms.
Wet loose avalanche activity can also be expected on sun-exposed slopes and below treeline. These avalanches are generally smaller than wet slabs but they can gather mass as they travel and reach low elevations.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are at their largest at this time of year, and become weaker with warm temperatures and solar radiation.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 21st, 2021 4:00PM
