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 14th, 2019–Feb 15th, 2019

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

Regions

North Columbia.

A persistent slab problem treeline and below continues to produce avalanches treeline and below. A conservative approach to terrain selection is recommended.

Confidence

High -

Weather Forecast

THURSDAY Night: Mainly cloudy with isolated flurries, light to moderate southeast wind, alpine temperature -9 C.FRIDAY: Scattered flurries, accumulation 5-10 cm , light to moderate southwest wind, alpine temperature -8 CSATURDAY: Flurries, accumulation 5-10 cm, light north wind, alpine temperature -10 CSUNDAY: Mix of sun and cloud, light northeast wind, alpine temperature -15 C

Avalanche Summary

On Wednesday a few size 1-1.5 wind slab avalanches were triggered naturally in the alpine on northwest and northeast aspects. Avalanche activity on Monday and Tuesday has been reported as naturally triggered size 1-2 wind slabs between 2000 and 2300 m on all aspects and also a few skier triggered size 1 and 2 persistent slab avalanches on northeast aspects between 1200 and 1900 m. On Saturday, a snowmobiler died in a large (size 2) slab avalanche in the Oventop Creek drainage (report here). It was triggered by the rider at 2100 m on a south aspect. The crown fracture varied from 15-100 cm deep, suggesting wind loading was a factor in the incident.

Snowpack Summary

There are two prominent, touchy weak layers in the snowpack that have been responsible for a several dangerous avalanches in the past 2 weeks. The upper layer was buried at the end of January and lies approximately 40 cm below the surface. The lower one was buried mid-January and lies approximately 75 cm below the surface. Both comprise a mix of surface hoar and facets and may lie on top of a sun crust on southerly aspects. Both layers are potentially reactive and in any given location, one or both could potentially exist in the snowpack. Wide propagation has been noted, meaning avalanches have the potential to be large (up to size 3). These weak layers are most prevalent at treeline and below, but may also be found in sheltered areas in the alpine.Average snow depths are approximately 300 cm. Very sporadically, failures have occurred near the base of the snowpack in or close to this region. These releases have almost all been from high alpine areas, possibly triggered close to rocky features.

Problems

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.

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.