Avalanche Forecast

Issued: Mar 14th, 2020 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

Wind slabs may be found in atypical terrain due to northeast wind. A warming trend could weaken cornices and the snow on sun-exposed slopes.

Summary

Confidence

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

Weather Forecast

SATURDAY NIGHT: Clear skies, light east wind, treeline temperature -7 C.

SUNDAY: Clear skies, moderate east wind, treeline temperature -2 C, freezing level rising to 1200 m.

MONDAY: Clear skies, light to moderate northeast wind, treeline temperature 4 C, freezing level 2300 m.

TUESDAY: Clear skies, light northwest wind, treeline temperature 4 C, freezing level 2200 m.

Avalanche Summary

There have not been reports of avalanche activity in the region since those reported in this MIN. The potential of triggering wind slab avalanches remains possible. Loose wet avalanche activity and cornice falls could also be triggered with the warming trend.

Snowpack Summary

A major warming trend is forecast for the coming days, which could rapidly weaken the snowpack and cornices. Wind slabs may be found on all aspects due to variable wind directions. Recent wind has blown from the northeast, forming fresh wind slabs in south to southwest terrain features at higher elevations. In sheltered terrain, about 30 cm of snow may overly a melt-freeze crust and potentially small surface hoar crystals.

The remainder of the snowpack is well-settled. The snowpack depth varies from around 300 to 400 cm around 1200 to 1400 m and tapers rapidly with elevation, with no snow below 700 m.

Terrain and Travel

  • Be aware of highly variable recent wind loading patterns.
  • Carefully evaluate steep lines for wind slabs.
  • Extra caution for areas experiencing rapidly warming temperatures for the first time.
  • Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Problems

Wind Slabs

An icon showing Wind Slabs

An atypical loading pattern with wind from the northeast has formed wind slabs on terrain features that may not often have them. Use extra caution as you approach steep slopes in exposed terrain, particularly near ridge lines.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

The snowpack will undergo a rapid change as the freezing level rises and clear skies prevail. For Sunday, loose wet avalanche activity is most likely during the heat of the day on sun-exposed slopes.

Aspects: South East, South, South West.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices are large at this time of year and they will undergo rapid weakening during this warming trend. Avoid travelling close to them while on ridges and limit your exposure on slopes beneath them.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 15th, 2020 5:00PM