Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Feb 18th, 2023–Feb 19th, 2023

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Below Threshold.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Below Threshold.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Below Threshold.

Regions

Yukon, Tutshi, Wheaton, White Pass East, White Pass West.

Carefully assess the wind effect as well as new snow amounts as you move through terrain. variable wind direction has been observed.

Confidence

Low

Avalanche Summary

No significant avalanches were reported in the last couple days but we suspect rider triggerable wind slabs will be found in exposed terrain. On Thursday our field team observed debris from a previous large persistent slab avalanche. At least once a week evidence of large persistent slab avalanches is reported. Keep this in mind when traveling in the backcountry.

Snowpack Summary

Over the past few days southerly winds and new snow has formed large wind slabs on north and east facing slopes. Our field team observed winds coming from a variety of directions so wind slab may exist on all aspects. In sheltered areas recent snow is still soft and likely makes for decent riding.

A hard melt-freeze crust that extends up to about 1700 m is now on the surface in wind-exposed terrain and otherwise buried about 50 to 80 cm in wind-loaded terrain. The crust appears to be bonding to the snowpack.

A weak layer of surface hoar and facets may be buried about 80 to 120 cm deep on north to east aspects in alpine and upper treeline elevations. The layer may rest on a harder melt-freeze crust. Where preserved, this layer has shown to have very high propagation potential and capable of producing large avalanches hundreds of metres wide.

Weather Summary

Saturday Night

Cloudy with up to 10cm of new snow possible. Moderate southwest winds and a low of -6 at 1500m.

Sunday

A mix of sun and cloud with flurries bringing up to 5cm of new snow. Light southwest winds and a high of -6 at 1500m.

Monday

Cloudy with flurries bringing up to 5cm of new snow. Light northerly winds and temperatures at 1500m falling throughout the day to -14.

Tuesday

Mostly clear with the possibility of light flurries bringing trace amounts of new snow. Moderate northerly winds and a high of -15 at 1500m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • The best and safest riding will be on slopes that have soft snow without any slab properties.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.