Avalanche Forecast

Issued: Mar 17th, 2020 4:00PM

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

Avalanche Canada shorton, Avalanche Canada

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Watch for unstable snow on sun-exposed slopes and steep wind-affected terrain. 

Summary

Confidence

High - We have a good understanding of the snowpack structure and confidence in the weather forecast

Weather Forecast

A high pressure system brings clear dry conditions for the week.

TUESDAY NIGHT: Clear skies, light north wind, freezing level drops to 1400 m, treeline temperatures drop to +2 C.

WEDNESDAY: Sunny, light north wind, freezing level remains steady around 1500 m with treeline temperatures reaching +4 C.

THURSDAY: Mostly sunny, light south wind, treeline temperatures around +4 C, freezing level around 1500 m.

FRIDAY: Sunny, light south wind, treeline temperatures around +4 C, freezing level around 1500 m.

Avalanche Summary

Over the weekend a few wind slab avalanches were human triggered, including a size 2 slab on a northeast slope on Brunswick Mtn, a size 1 slab on a west slope on the Lions, and a size 1 slab on a southeast slope in Tetrahedron.

Looking forward, loose wet avalanche activity and cornice falls could be triggered with the ongoing warming trend. The potential of triggering wind slab avalanches remains possible in steep alpine terrain.

Snowpack Summary

Surface conditions are highly variable with a mix of crusts, moist snow, and hard wind slabs. In sheltered terrain, about 30 cm of settled 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 300-400 cm around 1200 to 1400 m and tapers rapidly with elevation, with no snow below 700 m.

Terrain and Travel

  • Carefully evaluate steep lines for wind slabs.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Problems

Cornices

An icon showing Cornices

Cornices are large at this time of year and they will undergo rapid weakening when they warm up. 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

2.5 - 3.5

Wind Slabs

An icon showing Wind Slabs

Triggering wind slab avalanches remains possible after strong northeast wind formed slabs in atypical terrain features.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Mar 18th, 2020 4:00PM