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 27th, 2023–Mar 28th, 2023

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

Regions

Banff Yoho Kootenay, Banff, East Side 93N, Kootenay, Lake Louise, LLSA, Sunshine, West Side 93N, Field.

Strong solar inputs Tuesday will weaken the snowpack on southerly aspects. Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Confidence

Moderate

Avalanche Summary

Recent storm snow has been producing loose dry avalanches on steep terrain in the alpine. In addition, one new natural size 3 deep persistent slab was observed on the east side of HWY 93N Monday

On Saturday, two skier-triggered avalanches were reported. One on Massive Mountain and the other near Observation Sub Peak. These show that human triggering of various buried layers is still possible.

Snowpack Summary

5-20 cm of storm snow sits over buried temperature crusts to 1500 m, sun crusts to ridgetop on solar aspects, and facets on shaded slopes. The midpack in this area has several crust and facet layers 30-110 cm down, that remain a concern in steep terrain. The bottom of the snowpack consists of weak basal facets in many areas, with sudden test failures still occurring.

Weather Summary

A ridge of high pressure will bring clear skies to the region. Overnight alpine temps for Monday and Tuesday will be near -20 with daytime highs climbing to 0 at 2000m. Winds will remain light to moderate. Though temps will be cold overnight, strong solar inputs throughout the day will likely cause the upper snowpack to deteriorate.

Terrain and Travel Advice

  • Uncertainty is best managed through conservative terrain choices at this time.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • Cornices become weak with daytime heating or solar exposure.

Problems

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.

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.