Avalanche Forecast

Archived

Apr 20th, 2023–Apr 21st, 2023

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Regions

Yukon, Tutshi, Wheaton, White Pass East, White Pass West.

Recent wind has varied in direction so watch for lingering wind slabs on all aspects at upper elevations.

Confidence

Low

Avalanche Summary

No avalanches were reported on Wednesday. However, observations in this region are currently very limited.

Observations are limited at this time of year, please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.

Snowpack Summary

In the alpine, 20-30 cm of recent snow and moderate south wind formed wind slabs in isolated lee features. A robust crust exists on all aspects up to approximately 1400 m and to ridgetop on south aspects.

Cornices are large and loom over slopes below like gargoyles.

A weak layer of surface hoar/crust/facets buried in early January is now around 100 cm down in most areas. Operators continue to monitor this layer. A significant warming event or a large trigger (like a falling cornice) are the most likely things to activate this layer.

Weather Summary

Thursday Night

Partly cloudy / 20 km/h east ridgetop wind / Temperature at treeline around -4 C / Freezing level valley bottom

Friday

Mostly cloudy / 20 km/h east ridgetop wind / Temperature at treeline around -3 C / Freezing level 1200 m

Saturday

Mix of sun and cloud with isolated flurries; 0-10 cm / 20 km/h east ridgetop wind / Temperature at treeline around -2 C / Freezing level 1300 m

Sunday

Cloudy with isolated flurries; 0-5 cm / 20 km/h southeast ridgetop wind / Temperature at treeline around -1 C / Freezing level 1400 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Carefully evaluate steep lines for wind slabs.
Recent wind has varied in direction so watch for wind slabs on all aspects.
Cornice failure may trigger large avalanches.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.