Avalanche Forecast

Issued: Mar 16th, 2023 4:00PM

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

Avalanche Canada PW, Avalanche Canada

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While alpine air temperatures may be cool, the sun can still pack a punch. Watch for changing conditions as solar radiation increases in the afternoon.

Summary

Confidence

Moderate

Snowpack Summary

15-25 cm's of recent snow has fallen on a freshly buried (March 12) layer of surface hoar, facets and sun crust. The midpack comprises various Jan crust layers that are now down 60-100 cm. The weak Nov. 16 basal facet layer is down 60-150 cm producing sudden results in snowpack tests. The basal facets have become more triggerable with the additional load and warmth. Cornices also are quite large and will also be affected by solar inputs.

Weather Summary

The high pressure that we have been experiencing will stick around through Friday and into the weekend, with mainly sunny skies persisting.

Friday's alpine high will be -10 and valley bottoms will be as warm as +5, with freezing levels set at 1800m. Winds will continue to be light in the morning, but will creep up to 40 km/h by the afternoon out of the south/southwest.

Saturdays weather looks to be quite similar, however temperatures could be even warmer.

For a more detailed forecast click here.

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.

Problems

Storm Slabs

An icon showing Storm Slabs

Surface snow from the past few days may settle into a slab over a new weak layer buried on March 12. We are currently assessing this interface throughout the region. Avalanches may release from solar inputs Thursday. These avalanches may start small but then trigger a deeper layer and become large.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

We have seen increased activity on this layer. Multiple parties have remote triggered this problem from thin areas in the snow pack. Give careful consideration to the slopes overhead as large avalanches may run well into the runout zone or into lower-angle terrain. Avoid big terrain features and be especially cautious in thin or rocky areas, where triggering is more likely. The weak depth hoar at the bottom of the snowpack inspires little confidence and will continue to wake up with each new storm or warming event.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3.5

Persistent Slabs

An icon showing Persistent Slabs

Three persistent weak layers formed in January are down 60-110 cm. Buried sun crusts on steep solar slopes present the greatest concern for triggering, however, weak facets and isolated surface hoar can be found on the same interfaces on shaded aspects.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Mar 17th, 2023 4:00PM