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 15th, 2017–Feb 18th, 2017

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

Regions

Waterton Lakes.

Light precipitation on Thursday may not be enough to salvage the ski quality, but you can hone your skills in the new avalanche transciever practice area, across the road from the Little Praire trailhead!

Weather Forecast

The Jet Stream passes overhead, generating strong warm winds from the SW. The flow slackens/cools during Friday.Thursday: Light snowfall (5 - 25cm), except rain below 1800m, Strong SW winds, Freezing Level 2000m, surface refreeze expected at upper elevations.. Friday/Saturday: -3 to -8, Flurries, Moderate SW winds backing to Light Easterlies.

Snowpack Summary

Freezing Levels above mountaintop for 48 hours combined with sun have consolidated the upper snowpack, especially on solar aspects. A thick, cohesive storm slab is producing Moderate/Sudden test results on a Persistent Weak Layer down 40-80cm (crust on sunny slopes, facets in sheltered areas from 1700-2150m, basal facets in shallow snowpack areas.)

Avalanche Summary

On Tuesday, several small Loose Wet avalanches were observed in steep Alpine terrain. One of these triggered a small (Size 1.5) Storm Slab in extreme terrain. On Wednesday, widespread snowballing was noted.

Confidence

Forecast snowfall amounts are uncertain on Thursday

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

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.

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.