Spring conditions will extend to mountain tops as freezing levels skyrocket over the week. Minimize exposure to avalanche terrain in the heat of the day, particularly steep and sun-affected slopes.
Summary
Confidence
Moderate
Avalanche Summary
Observations are very limited at this time of year, please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.
As temperatures increase, natural avalanche activity and human triggering becomes more likely. Particularly from steep and sun-affected terrain features.
A rider-triggered avalanche was reported on Friday around 50 cm deep on a convex roll. Check out the MIN post for more details.
Snowpack Summary
Warm temperatures will weaken the surface snow to mountain top as freezing levels rise on Tuesday, breaking down surface crusts and moistening any previously dry snow at high elevations. Sun-affected terrain will see the most intense warming, likely creating wet and slushy snow.
Previous storm snow was heavily wind affected, with deeper deposits found on north-facing terrain features, sitting over a widespread crust that extends to most mountain peaks. This crust is expected to form an ideal sliding surface for avalanche activity.
The middle and lower snowpack are strong and well-bonded. As warming continues, particularly with extended periods of mild overnight temperatures, these layers may weaken, increasing the potential for deeper avalanches.
Weather Summary
Monday Night
Partly cloudy. Moderate westerly wind. Freezing level remain above 1300 m. No snowfall expected.
Tuesday
A mix of sun and cloud with freezing levels rapidly rising above 2500 m over the day. Treeline temperatures around +8 °C. Moderate westerly winds.
Wednesday
A mix of sun and cloud with freezing levels steady around 2700 m. Treeline temperatures around +10 °C. Strong westerly winds. Flurries possible, with trace accumulations likely in the east and up to 10 cm in the west.
Thursday
Full sun with freezing levels rocketing to 3500 m. Treeline temperatures above +10 °C. Light northwest winds.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
- Rocks will heat up with daytime warming and may become trigger points for loose wet avalanches
- Keep in mind that wet avalanches can be destructive due to their high density.
Problems
Loose Wet
Avoid slopes that have moist or wet surface snow in the afternoon when warming is expected to be most intense. Warming will be amplified on steep, sun-affected slopes around rocky outcrops.
Stick to shaded slopes earlier in the day if you choose to venture out, and head out of the backcountry before peak warming.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Large and looming cornices will become weak with rising temperatures and sunshine. Cornices pose a significant hazard on their own to backcountry users and may trigger avalanches if they fall on the slope below.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 25th, 2023 4:00PM
