Avalanche Forecast
Issued: Apr 6th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs, Loose Wet and Cornices.
swerner,
Avalanche Canada
Recent storm snow combined with significant warming and solar radiation are driving the avalanche hazard to HIGH, especially by the afternoon.
Check out the Forecaster Blog for additional details.
Summary
Confidence
Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.
Weather Forecast
Thursday: Cloudy with sunny periods in the morning. WARM. Freezing levels rise to 2500 m by the afternoon. Alpine temperatures +3C and ridgetop wind moderate to strong from the southwest.Â
Friday: No overnight refreeze and WARM. The freezing level should start to drop by midday. Cloudy with snow above 1500 m, 10-15 cm. Ridgetop winds strong from the southwest.
Saturday: Cloudy and cold with new snow up to 10 cm. Freezing levels drop to the valley bottom and ridgetop winds switch to the northwest.Â
Avalanche Summary
On Tuesday, solar induced dry loose and storm slab avalanches were reported up to size 2.Â
On Monday, numerous natural and rider-triggered wind and storm slabs up to size 2 were reported. Some dry loose avalanches were also seen from steep terrain features up to size 1. Â
Warm temperatures and solar radiation will likely trigger a natural avalanche cycle on Thursday and Friday
Snowpack Summary
Thursdays warming will likely create moist/ wet surface snow on all aspects and elevations beside high true North slopes.Â
Up to 25 cm of new storm snow fell at upper elevations. Strong west to southwest wind will be redistributing the new storm snow in exposed high elevation terrain forming wind slabs and developing large cornices. The upper 60 cm of the snowpack consists of multiple buried crusts.Â
The new snow brings 50-70 cm of snow above the late March melt-freeze crust and tapers rapidly at lower elevations.Â
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Terrain and Travel
- Avoid all avalanche terrain during periods of intense solar radiation.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
- Cornices become weak with daytime heating or solar exposure.
Problems
Persistent Slabs
50-70 cm of recent storm snow sits above a crust at treeline and above. Warming and solar radiation will likely consolidate the new snow into a reactive slab, producing large avalanches.
Avalanches may start as dry slabs in the alpine but entrain wet snow and run into below treeline elevations.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Sun and warm temperatures will weaken the snow surface on most aspects and elevations but especially on sun-exposed slopes, creating wet avalanches.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Springtime cornices are large and unpredictable. The sunshine can pack a punch and lead to cornice failures. Give them a wide berth when travelling at ridge crest and avoid overhead exposure.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 7th, 2022 4:00PM
