Avalanche Forecast
Issued: Apr 13th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Cornices and Wind Slabs.
kdevine,
Avalanche Canada
Warm temperatures and sunshine will weaken cornices and the snowpack. Avoid exposure to sun exposed slopes and cornices, especially in the afternoon.
Check out the latest Forecaster's Blog for more detailed information on managing these conditions.
Summary
Confidence
Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.
Weather Forecast
A ridge of high pressure, with sunny skies and high freezing levels will dominate the weather pattern this week.
Tuesday night - Mainly clear / moderate northeast wind / alpine low temperature near -1 / freezing level 1500 m, possible alpine temperature inversion
Wednesday - Mainly sunny / light to moderate northeast wind / alpine high temperature near 1 / freezing level 2500 mÂ
Thursday - Mainly sunny / moderate northeast wind / alpine high temperature near 2 / freezing level 2700 mÂ
Friday - Mainly sunny / light northeast wind / alpine high temperature near 3 / freezing level 2900 m
Avalanche Summary
There were a few size 1-1.5 human triggered wind slab avalanches reported over the past week. Small natural dry loose avalanches were also reported in the Kootenay Pass area.
Looking forward, wet loose avalanches are expected on steep solar aspects with sunny weather and rising freezing levels. Cornice failures will also become more likely. Wind slabs may remain reactive in leeward terrain featuresat upper elevations.
Snowpack Summary
A crust exists on the surface on solar aspects, and on all aspects up to about 1800 m. Dry snow can still be found on north aspects at higher elevations. Sunshine and rising freezing levels are expected to soften the surface crust during the day. The mid and lower snowpack are well settled and strong.
Terrain and Travel
- Avoid sun exposed slopes, especially if snow surface is moist or wet.
- Loose avalanches may start small but they can grow and push you into dangerous terrain.
- Cornices become weak with daytime heating or solar exposure.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Carefully evaluate steep lines for wind slabs.
Problems
Loose Wet
Surface snow will tend to lose cohesion and become unstable with solar warming during the day. Avoid exposing yourself to terrain where a small wet loose avalanche could have big consequences.
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
Wind Slabs
Wind slabs in lee terrain may still react to human triggers.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 14th, 2021 4:00PM
