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 29th, 2023–Mar 30th, 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 possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.

Regions

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

Strong solar input will continue Thursday, although if clouds come over it may stay cooler. Avoid exposure to sun-exposed slopes, especially late in the day. Now is the time to make the habit of starting the day early, and finishing early.

Confidence

Moderate

Avalanche Summary

Ski hills and road patrols today were reporting some loose wet avalanches on solar aspects to size 1. Yesterday, one of the local ski hill snow safety teams triggered a size 2.5 with explosives in terrain that had seen extensive previous skiier compaction. This illustrates the unpredictability of the current snowpack and how even with previous traffic, the deep layers can still be triggered with relatively small loads (single hand charge).

Snowpack Summary

Surface crusts exist to ridgetop on solar aspects. On polar aspect, 10-25cm of storm snow sits over a facetted interface from March 25th and buried temperature crusts below 1500 m. The midpack in this area has several crust and facet layers 30-110 cm down, which remain a concern in steep terrain. The bottom of the snowpack consists of weak basal facets in many areas, with sudden test results still occurring.

Weather Summary

Thursday looks to be another mainly sunny day. Air temperatures will start cool but the solar radiation will make solar aspects feel warm unless clouds come over.

Friday and Saturday will see a change in the weather as a low moves in from the coast. Expect increasing cloud on Friday and light snow by the afternoon as alpine winds pick up to strong from the SW.

Expect a few cm's overnight Friday and 5-10 cm on Saturday.

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.