Avalanche Forecast

Issued: Mar 2nd, 2023 1:45PM

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

Avalanche Canada mkoppang, Avalanche Canada

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Westerly winds and up to 10cm of snow on Thursday is adding more load to the current windslab problem at treeline and above. Be aware of the potential for large avalanches that involve the entire winters snowpack. Thin snowpack areas should be avoided.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches were observed on Thursday but visibility was limited due to snowfall during the day and associated clouds.

Snowpack Summary

Up to 35cm of recent storm over the past few days is being moved around by the strong winds creating and adding to the previous windslabs that existed in the region. Field teams have been finding easy shears down 25-35cm, and these shears that are reactive to skier traffic. Moderate shears also persist down 30 to 50cm on various versions of old wind slab interfaces. The midpack is strong in deeper snowpack regions near the divide, but the basal facets/depth hoar persist. An avalanche initiated in the upper snowpack could easily step down to the deep persistent weak layers, causing a very large avalanche. Always have full depth avalanche on your mind.

Weather Summary

Strong SW winds continued on Thursday but are forecast to become more moderate by friday morning. Another 5cm of snow is likely to fall overnight with temperatures around -15 in the morning warming up to -11 by mid day. Its still full on winter out there these days!

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent variable strong winds have created and added to previous windslabs that formed in Alpine and treeline areas. In addition, there are several iterations of buried wind slabs formed in previous wind events down 30 to 50cm in the snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The alpine is still variable in total amounts of snow but the basal layers haven't changed. The entire lower half is either facets, or depth hoar. Thin weak areas should be treated as suspect and avoided.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3.5

Valid until: Mar 3rd, 2023 4:00PM