Avalanche Forecast

Issued: Mar 23rd, 2023 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Deep Persistent Slabs.

Avalanche Canada jpercival, Avalanche Canada

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Watch for lingering wind slabs that may remain reactive to human triggering.

Summary

Confidence

Moderate

Avalanche Summary

On Wednesday, avalanche activity has begun to subside as only a few small ( size 1) loose wet avalanche were reported and initiated from very steep south aspect terrain at treeline elevations and below. On specific terrain features such as smooth rock slabs, glide slab cracking and buckling was reported,

On Tuesday A few naturally triggered small loose wet avalanches were observed with one large (size 2) that initiated in a steep rocky feature in the alpine running onto the glacier below. A noted natural small (size 1) wind slab avalanche on a northeast aspect in the alpine was reported. Additional reports of large (size 2) glide slab avalanches occurring on a south aspect in terrain with rock slab features being the ground roughness characteristic.

On Monday, numerous small wet loose avalanches (size 1) were observed on steep, rocky solar slopes at higher elevations.

On Sunday, several loose wet, large (size 2), avalanches were observed below treeline. A skier controlled, small (size 1), wind slab avalanche was reported at 1400 m on a northeast aspect.

If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

Variable winds have built wind slabs on exposed terrain features near ridgetop. Below 1800 m moist snow or a refrozen melt freeze crust covers the surface. The crust extends up to 2000 m on solar aspects.

The middle of the snowpack is strong and contains numerous hard crusts.

The lower snowpack is composed of weak basal facets. This layer has produced limited recent avalanche activity, however it can quickly become active again with any significant change to the snowpack, such as rapid loading (heavy snowfall or rain) or prolonged and extensive warming.

Weather Summary

Thursday Night

Mainly cloudy with snowfall, 1 to 5 cm of accumulation. Light northeast winds at ridgetop. Treeline temperature -3°C. Freezing levels 500 m.

Friday

Cloudy with isolated flurries, trace amounts of accumulation. Light northwest winds at ridgetop. Treeline temperature 0°C. Freezing levels 1000 m.

Saturday

Cloudy with no new precipitation. Light northwest winds at ridgetop. Treeline temperature 0°C. Freezing levels 1000 m.

Sunday

Cloudy with no new precipitation. Light east winds at ridgetop. Treeline temperature 0°C. Freezing levels 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be carefull around freshly wind loaded features.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Storm snow has been redistributed by switching winds and creating deeper deposits in exposed alpine and treeline features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Weak, sugary faceted grains exist near the base of the snowpack. Riders are most likely to trigger this layer on steep, rocky slopes where the snowpack is thin and shallow. The likelihood of avalanche activity on this layer will increase during periods of rapid change to the snowpack, such as heavy snowfall, rain, or rapid warming. Cornices are also very large at this time of year and a cornice failure could trigger this layer.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3.5

Valid until: Mar 24th, 2023 4:00PM