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 cautiously with an assessment mindset on Saturday and expect the reactivity of new snow to increase with elevation and wind effect. Be especially cautious around steep slopes being hit by the sun. This is where natural avalanches will be most likely.
Summary
Confidence
Weather Forecast
Friday night: Continuing snowfall bringing new snow totals to 15-25 cm. Strong southwest winds shifting west as snowfall eases.
Saturday: A mix of sun and cloud. Light to moderate northwest wind. Alpine high temperatures around -9 with freezing levels to 1000 metres.
Sunday: Mainly sunny. Light variable winds. Alpine high temperatures around -5 with freezing levels to 1500 metres.
Monday: Sunny. Light northeast winds. Alpine high temperatures around -3 with freezing levels to 1700 metres.
Avalanche Summary
Fresh storm slabs will continue build overnight and will very likely be reactive to human triggering on Saturday, especially where wind loading occurs. Expect snow to shed naturally from sun-exposed slopes during the day.
Small (size 1) natural wind slab were observed with ongoing wind transport of recent snow in the Whistler area on Thursday.
A natural avalanche cycle was observed in the region on Saturday during the last storm. On Sunday, there were a few size 1-1.5 human triggered wind slab avalanches reported. This MIN describes triggering a small wind slab in large terrain.
Snowpack Summary
15-25 cm of new snow is expected to accumulate by Saturday morning, bringing the total this week to about 25-40 cm. Strong southwest winds are expected to accompany the new snow, likely forming fresh and reactive slabs in many areas.
The recent storm snow sits on a crust on sun-exposed aspects, and on all aspects below about 1600 m. It likely sits on soft snow or wind slabs on north aspects.
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.
- Choose conservative terrain and watch for clues of instability.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
A widespread storm slab problem will continue to take shape over Friday night, meaning touchy avalanche conditions for Saturday. These conditions may be particularly heightened in the south of the region where greater snowfall typically accumulates. The new snow will be especially sensitive to human triggers at higher elevations where wind loading has occurred and will likely shed naturally from steep, sun exposed slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are large and looming along many ridgelines, and have likely grown with recent fresh snow and wind.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 10th, 2021 4:00PM
