Avalanche Forecast

Issued: Mar 19th, 2023 4:00PM

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

Avalanche Canada GL, Avalanche Canada

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The region is trending towards spring like conditions. Start early and finish early as the sun is having the strongest effect typically by mid-afternoon. It is wise to choose ice climbs with no overhead hazard and least amount of overall sun exposure.

Summary

Confidence

Moderate

Avalanche Summary

Sunday's Icefield patrol noted several low elevation loose wet slides up to size 2. A couple of these were at higher elevation solar aspects. A few deep slabs were also noted on alpine East aspects. Saturday at 5pm a size 2 loose wet roadside slope hit highway 93 burying both lanes for 10metres. A large, likely ice or cornice triggered and solar influenced avalanche, was directly observed at 1:30 in the Stutfield valley. See MIN report.

Don't forget to post avalanche observations to the MIN.

Snowpack Summary

A suncrust has formed on solar aspects at all elevations. This caps off the 15-20cm of new snow from March 13th. Moderate SW winds after March 13th created pockets of windslab on lee aspects. Approximately 20-30cm down is a buried sun crust at low elevations on steep southerly slopes and a surface facet layer in sheltered terrain. The mid-pack is 40 to 80cm of supportive snow. Near the ground it is generally weak with large facets and depth hoar.

Weather Summary

Monday will be sun and cloud, -4 °C, light Northeast winds, and 1700 metres freezing level. Tuesday and Wednesday will be similar except for 2200 metres freezing level on Wednesday.

Detailed weather forecasts from Avalanche Canada: https://www.avalanche.ca/weather/forecast

Terrain and Travel Advice

  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Be alert to conditions that change with elevation and sun exposure.

Problems

Loose Wet

An icon showing Loose Wet

Loose wet snow avalanche activity is increasing as afternoons are getting dramatically warm. These types of avalanches can be what initiate larger slag avalanches. Temperatures are ranging from -15 at night to +8 in the afternoon.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

The 20cm of storm snow from March 13th has been periodically blown around, redistributed, settled, and has combined with the larger snowpack structure for the most part. Their is a cornucopia of interfaces throughout the snowpack depending on aspect, elevation, and local terrain influences. There have been a few avalanches this past week which appeared to have stepped down to multiple layers. Sun will increase potential reactivity.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Wind slab avalanches have stepped down to the deep persistent slab since the last storm meaning large triggers can influence this basal weakness. The likelihood is slowly increasing for this high consequence avalanche problem.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3.5

Valid until: Mar 20th, 2023 4:00PM

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