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 is driving the avalanche hazard to HIGH, especially by the afternoon.
Check out the Forecaster Blog for additional details.
Summary
Confidence
Moderate -
Weather Forecast
Thursday: Cloudy with some 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. Cloudy with snow above 1500 m 10-15 cm. Freezing levels stationary at 2500 m with alpine temperatures near +3C. The freezing level should start to fall overnight and into Saturday.
Saturday: Cloudy with new snow up to 10 cm. Freezing levels drop to the valley bottom and ridgetop winds switch to the northwest.Â
Avalanche Summary
No recent reports since last weekend.Â
Warm temperatures and will likely trigger a natural avalanche cycle on Thursday and Friday
On Sunday, a small natural wind slab avalanche was observed on a north aspect in the alpine. A rider triggered a small slab avalanche on the same slope. Both avalanches likely occurred on Saturday.
On Saturday, many natural dry loose avalanches were reported in steep terrain, as well as a large cornice failure that released a slab on the slope below.Â
Snowpack Summary
Thursday's warming will likely create moist/ wet surface snow on all aspects and elevations besides high true North.
25 to 50 cm of new storm snow blankets upper elevations with the greater snowfall amounts being in the Renshaw. Strong west to southwest wind will be redistributing the new storm snow in exposed high elevation terrain forming touchy wind slabs and developing large cornices. The upper 60 cm of the snowpack consists of multiple crusts.Â
30-70 cm of snow sits on the thick melt-freeze crust from late March.Â
Terrain and Travel
- Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Cornices become weak with daytime heating or solar exposure.
- The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
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
Even brief periods of sunshine combined with 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 and warming 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
