Avalanche Forecast

Issued: Jan 23rd, 2022 4:00PM

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

Tim Haggarty,

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http://www.pc.gc.ca/apps/links/goto_e.asp?destination=http://www.avalanche.ca/spaw/2022-01-20-spaw

As temperatures cool and the winds back off Monday, we expect the hazard to do the same.

Be aware that it is still heads-up hockey out there with both lingering wind slabs and the persistent slab problem producing recent avalanches.

Summary

Weather Forecast

As a trough moves south through Alberta Monday, the region will see patchy cloud and possibly a few light flurries as temperatures cool a few degrees. Winds are expected to shift north and back to light to moderate speeds. The winds look to rebound Tuesday as do the temperatures which may reach -5C in the alpine.

Snowpack Summary

Wind effect and wind slabs in the alpine and exposed tree-line areas. New sun crusts can be expected steep solar slopes . 30 to 60 cm of recent snow lies over a facet interface formed in late December. The Dec. 2 crust and facets are generally 100-150cm deep producing hard to no results. Snow depth at tree-line is around 200-250 cm.

Avalanche Summary

No new avalanches observed or reported Sunday. Avalanche control in Yoho last week produced slabs with every shot. Most were failing on a wind slab or facet layer 40-60cm deep and then entraining facets in the track. One stepped down to the November facets ~ 180 cm deep.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Tuesday

Problems

Wind Slabs

An icon showing Wind Slabs

Recent winds have created wind-slabs in the alpine and some tree-line locations. These slabs are now 3-4 days old and we expect their sensitivity to decrease however they may be found over facets in some locations and remain sensitive.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

This problem represents both the Dec. 2nd crust/ facet layer (treeline and below) and layers of faceted snow that were formed during the late December cold snap (all elevations). If triggered, either layer will result in large avalanches.

  • Forecasters are operating with alot of uncertainty at this time.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 24th, 2022 4:00PM