Avalanche Forecast

Issued: Mar 16th, 2021 3:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Loose Wet and Cornices.

Avalanche Canada jcoulter, Avalanche Canada

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Avalanche hazard will rise with daytime warming and solar input. Time your day to move off of slopes before they get moist or slushy and steer clear of overhead hazards like cornices.

Summary

Confidence

Moderate - Uncertainty is due to how the snowpack will react to the forecast weather. Uncertainty is due to difficult to forecast freezing levels.

Weather Forecast

TUESDAY NIGHT: Mostly clear, light south east wind, alpine low -4, freezing level to valley bottom in most parts of region.

WEDNESDAY: Sunny, light to moderate south west wind, alpine high +6, freezing level 2300 m.

THURSDAY: Mix of sun and cloud, light to moderate south west wind, alpine high +8, freezing level 2500 m.

FRIDAY: Increasing cloud, flurries possible, moderate to strong south west wind, freezing level 1600 m.

Avalanche Summary

Wet loose avalanches in the size 1-2 range have been reported from alpine and treeline elevations over the past few days. A couple of recent cornice falls from the last week have been noted as well. A small (size 1) wind slab was triggered accidentally near Fernie on Saturday. On Thursday-Friday a few solar triggered slabs up to size 2 were noted.

Snowpack Summary

The alpine may be wind affected in open areas. Snow on all solar aspects and lower elevation bands will start out crusty but may get moist by mid morning. Reports suggest snow on northerly terrain above 1600 m has so far remained dry. Cornices are large and looming, and glide cracks are increasing in size...both should be considered unpredictable and given a wide berth.

Around 30 to 50 cm of snow sits above a layer of sugary faceted grains that were buried in mid-February. In some areas, there may be an old layer of feathery surface hoar or facets from late January down 50 to 80 cm deep. There have been no reported avalanches on either of these layers in the region in the last 10 days, but there is always lingering concern that consecutive days in a row of warm temperatures may increase the reactivity of deeper weak layers in isolated areas.

Terrain and Travel

  • Be alert to conditions that change with aspect and elevation.
  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • Cornices become weak with daytime heating or solar exposure.

Problems

Loose Wet

An icon showing Loose Wet

Sun and warm daytime temperatures can quickly destabilize solar slopes and increase the likelihood of avalanches. Pinwheeling and a moist snow surface are signs that the stability of the upper snowpack is decreasing. 

Even small avalanches can be a hazard in high consequence terrain and above terrain traps.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices are large and likely weakening with sun and significant daytime heating. Big cornice falls are a hazard on their own but can also trigger avalanches on the slopes below. 

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 17th, 2021 4:00PM