Avalanche Forecast
Issued: Apr 9th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Cornices.
cgarritty,
Avalanche Canada
Ease into terrain in an assessment mindset, expecting reactivity of new snow to increase with elevation, wind effect, or sun exposure. Danger in the north of the region may be a step lower, but gather solid information (new snow depth/reactivity) before committing to your line.
Summary
Confidence
Weather Forecast
Friday night: Continuing flurries bringing new snow totals in the north of the region to about 15 cm, closer to 25-30 cm in the south of the region. Strong southwest wind shifting west as snowfall eases.
Saturday: Mainly cloudy. Light to moderate northwest winds easing over the day. Alpine high temperatures around -8 with freezing levels to 1200 metres.
Sunday: Sunny. Light variable winds. Alpine high temperatures around -3 with freezing levels to 1700 metres.
Monday: Mainly sunny. Light northeast winds. Aline high temperatures around -3 with freezing levels to 1700 metres.
Avalanche Summary
The region will likely see a north/south split in conditions for Saturday, with a more widespread and reactive storm slab problem likely to form in the south of the region and more limited new wind slab distribution in the north. Whatever accumulates locally, any solar exposure will likely cause it to shed naturally from steep, sun exposed slopes during the day.
A natural avalanche cycle was observed in the region on Saturday during the last storm.
Snowpack Summary
5-10 cm of snow is expected to fall on Friday, bringing this week's storm snow totals to about 15-30 cm. The Coquihalla could see up to 30 cm of new snow, bringing totals there closer to 40-50 cm. Strong southwest wind is forecast for the storm, meaning thicker, touchier wind slabs are likely to form in exposed leeward terrain.
The recent storm snow sits on a crust in most areas, except on north aspects above about 1500 m where it sits on either wind slabs or soft snow.
Cornices are large and looming along ridgelines. Their release is unpredictable, requiring a large berth if you're travelling above or below them.
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Even brief periods of direct sun could produce natural avalanches.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
Expect a north/south split for conditions on Saturday, with reactive new wind slabs scattered across in leeward terrain in the north of the region and a more widespread and reactive storm slab problem in the south (Coquihalla). Any solar exposure that occurs on steep slopes will likely cause loose snow to shed naturally.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are large and looming along many ridgelines, and have likely formed fragile new growth with recent snow and wind.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 10th, 2021 4:00PM
