Avalanche Forecast
Issued: Mar 30th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
swerner,
Avalanche Canada
Snowfall amounts are uncertain and the reactivity of fresh storm and wind slabs may increase through the day. The avalanche hazard reflects snowfall accumulations greater than 20 cm, if you see less the hazard may be MODERATE.
Summary
Confidence
Weather Forecast
Yet another Pacific frontal system hits the region Tuesday night bringing strong wind and new storm snow. Forecast snow amounts will vary across the region.
Wednesday: Snow will accumulate through the day 10-20 cm. Ridgetop wind strong from the South. Alpine temperatures near -3 and freezing levels 700 m.
Thursday: Snow amounts 10-20 cm. Ridgetop wind strong from the southwest and freezing levels 500 m.
Friday: Continued flurries 5-10 cm. Ridgetop wind strong from the southeast with freezing levels 700 m.
Avalanche Summary
Avalanche activity is expected to increase with Wednesday's storm. Snowfall amounts are uncertain and reactive storm and wind slabs may build through the day.
On Tuesday, several natural and explosive triggered wind slab avalanches occurred up to size 2.
Snowpack Summary
Storm snow amounts will build through the day on Wednesday. Storm slabs may become reactive to skier and riders by the afternoon.
30-60 cm of snow fell last weekend. This was accompanied by strong southwest then northwest wind. Wind slabs may continue to be reactive at upper elevations on leeward slopes. Much of the recent precipitation fell as rain at lower elevations and the snow surface below treeline is a melt-freeze crust in many areas.
At higher elevations, the new snow has added significant load to a couple of deeply buried weak layers. The first persistent weak layer was buried in mid-March and is around 100-180 cm deep. It consists of surface hoar on sheltered northerly aspects around treeline and down between 150 to 250 cm is another layer of surface hoar and facets, buried in mid-February. At this time, these layers linger in the snowpack but haven't been a reactive avalanche problem.
The mid and lower snowpack is well settled and strong in most areas.
Terrain and Travel
- Watch for fresh storm slabs building throughout the day.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Start with conservative lines 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
Reactive storm slabs are expected at upper elevations, especially in wind loaded areas where fresh wind slabs may be the primary concern. A change in wind direction means that wind loading may be found on many aspects.
With so much new snow, keep in mind that short periods of direct sun could trigger natural avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 31st, 2021 4:00PM
