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

Jan 26th, 2015–Jan 27th, 2015

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

Regions

Purcells.

The BC interior is experiencing record warm temperatures. Conservative decision making is recommended until conditions cool off.

Confidence

Good - Freezing levels are uncertain

Weather Forecast

A cold front will start to push the record breaking warm temperatures out of the interior by Tuesday afternoon.  Freezing levels are expected to return to valley bottom early Wednesday afternoon. The region may see isolated flurries and/or showers in the wake of the front. Winds will be light to moderate from the southwest.

Avalanche Summary

We are still in a complex avalanche scenario where touchy conditions are likely to persist. A snowpack with several critical avalanche layers has been stressed first by new load and now by record breaking warm temperatures.  This is resulting in a prolonged and widespread avalanche cycle.  Until we see a cooling in temperatures I anticipate that large natural avalanches will remain possible and human triggered avalanche likely as the upper snowpack continues to adjust.  The mid-January surface hoar layer has been responsible for the majority of the recent avalanche activity, however, I suspect that a large enough trigger in the right spot could have the potential to wake up the deeper mid-December surface hoar especially in open terrain at treeline.

Snowpack Summary

The upper snow pack is settling rapidly and moist snow can be found at the surface on all aspects and elevations.  The depth of the weak layer of surface hoar and crust buried in mid-January is highly variable across the region but in most places can be found between 20 and 40 cm below the surface. It remains my greatest concern.  The mid-December surface hoar layer lies below a strong mid-pack down 60 to 120cm and appears to be gaining strength.    The mid-November weak layer of crusts and facets can still be found near the bottom of the snowpack and has lately been unreactive.

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.

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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.