Avalanche Forecast

Issued: Mar 28th, 2023 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Deep Persistent Slabs and Loose Wet.

Avalanche Canada AB, Avalanche Canada

Email

Strong solar input will continue Wednesday. Avoid exposure to sun-exposed slopes, especially late in the day. Now is the time to make the habit of starting the day early, and finishing early.

Summary

Confidence

Moderate

Avalanche Summary

On a road patrol to Kootenay, deep slabs up to size 3 were observed on Mt Whymper and the Tumbling Peak area. These slides occurred within the last 24 hours. Solar radiation is a possible trigger.

Snowpack Summary

10-25cm of storm snow from the last 4 days sits over buried temperature crusts to 1500 m, sun crusts to ridgetop on solar aspects, and facets on shaded slopes. The midpack in this area has several crust and facet layers 30-110 cm down, which remain a concern in steep terrain. The bottom of the snowpack consists of weak basal facets in many areas, with sudden test results still occurring.

Weather Summary

On Wednesday, light and variable wind, a mix of sun and cloud, and cool radiant air temps (valley high of 5 deg and alpine -10) are expected. Solar radiation could be intense, despite cool-ish radiant air temperatures.

Terrain and Travel Advice

  • Uncertainty is best managed through conservative terrain choices at this time.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • Cornices become weak with daytime heating or solar exposure.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The lower snowpack consists of several weak layers that remain a concern.  A combination of basal facets, and crusts are still possible to trigger. Give careful consideration to overhead hazard as large avalanches may run into lower-angle terrain. Avoid big steep terrain features and places where large triggers could impact the slopes below. Be cautious in thin or rocky areas, where triggering the basal weakness is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3.5

Loose Wet

An icon showing Loose Wet

Strong solar inputs and upto 25cm of recent storm snow will likely produce loose wet avalanches on Southerly aspects. Pinwheeling and melting snow near rock are good indicators that the snowpack is being affected by solar radiation.

Aspects: South East, South, South West, West.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 29th, 2023 4:00PM