Avalanche Forecast
Issued: Mar 23rd, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
ahanna,
Avalanche Canada
Human triggered avalanches are likely at upper elevations, while wet and crusty snow makes for difficult travel conditions down low. Stick to low consequence terrain.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
Wednesday night: Flurries around 5 cm. Moderate southwest wind. Alpine low around -8 °C. Freezing level dropping to valley bottom.Â
Thursday: A mix of sun and cloud. Moderate southeast wind. Alpine high around -6 °C. Freezing level 1200 m.
Friday: Mostly cloudy. Moderate south wind. Alpine high around -5 °C. Freezing level 1200 m.
Saturday: Mostly cloudy. Light southeast wind. Alpine high around -5 °C. Freezing level 1100 m.
Avalanche Summary
Avalanche conditions were touchy on Wednesday. Skiers and machines remotely triggered storm slabs size 1.5-2.
A widespread natural avalanche cycle occurred on Tuesday. Storm slabs up to size 2 ran at upper elevations and loose wet to size 3 at lower elevations. Some of these avalanches stepped down to the persistent weak layer.Â
Prior to the storm, reports of persistent slab avalanches were steadily coming in over the last week from northwest of Terrace. These avalanches were large to very large (size 2-3), failing on a weak layer buried 60-100 cm deep mostly on northeast facing slopes. These avalanches were easily triggered by riders and vehicles, some remotely or sympathetically, and propagating long distances.
Snowpack Summary
30-50 cm of recent snow has seen variable wind effect at upper elevations. Below 1500 m, new snow depths taper and the snow may sit over a wet or crusty upper snowpack.
A weak layer of surface hoar is now buried 70-120 cm deep. A thick rain crust from mid-February 130-200 cm deep caps a well consolidated lower snowpack.
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Problems
Storm Slabs
30-50 cm of new snow fell at upper elevations with strong wind on Tuesday. Storm slabs likely remain triggerable by riders, especially in wind loaded terrain features. If triggered, storm slab avalanches have potential to step down to deeper layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
We have uncertainty as to whether a layer of surface hoar buried 70-120 cm deep remains a problem after a warm storm accompanied by a widespread natural storm slab avalanche cycle on Tuesday may have triggered it in areas where it posed a problem.
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 24th, 2022 4:00PM
