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

Mar 3rd, 2021–Mar 4th, 2021

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

Regions

North Columbia.

Warm temperatures and sunshine will elevate avalanche conditions across the region. Stick to low angle shaded terrain. Conditions in the northern end of the region (e.g. Clemina) are extra concerning due to a weaker snowpack structure.

Confidence

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

Weather Forecast

A ridge of high pressure brings dry, warm, and sunny weather.

WEDNESDAY NIGHT: Clear skies, light south wind, treeline temperatures drop to -6 C.

THURSDAY: Sunny, moderate south wind, freezing level climbs to 2000 m with treeline temperatures around 0 C.

FRIDAY: Cloudy with some isolated flurries, moderate south wind, freezing level climbs to 1800 m with treeline temperatures around -1 C.

SATURDAY: 5-10 cm of new snow by the morning then some sunny breaks in the afternoon, light southwest wind, freezing level climbs to 1400 m with treeline temperatures around -4 C.

Avalanche Summary

On Thursday the primary concern is natural avalanches on steep sun-exposed slopes. These will most likely present as wet loose avalanches, but larger wind and persistent slab avalanches are also possible. Read the latest Forecaster Blog for concerns about the warming.

Since the weekend, avalanche activity has primarily been limited to small (size 1) wind slab and dry loose avalanches on a variety of aspects with a few isolated larger cornice and wind slabs that released naturally.

Persistent slab avalanche activity has dramatically declined in the past week, with the last reports on Feb 24 (two size 3 explosive triggered avalanches on the late January weak layer) and Feb 26 (a size 2 human triggered avalanche in a cutblock on the February facet layer). While persistent weak layers are trending towards being unreactive, the current warming trend could temporarily heighten the likelihood of avalanches. 

Snowpack Summary

Rising freezing levels and sunshine will be melting, and potentially destabilizing, snow surfaces the next few days. Higher elevations have been impacted by recent wind from the southwest, likely leaving wind slabs lurking on shaded north and east slopes.

The lower snowpack has been strengthening with reactivity on persistent weak layers on the decline. The two layers of concern have been a layer of facets that was buried in mid-February (60-100 cm deep) and a layer of surface hoar and/or crusts that was buried in late January (80-120 cm deep). The impulse of warming over the next few days will likely be the final test on these layers, as there is some uncertainty about whether they will become reactive with warming temperatures.

Terrain and Travel

  • Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
  • Avoid exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
  • The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.

Problems

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

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.