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 18th, 2023–Feb 19th, 2023

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

Regions

Lizard-Flathead, South Rockies, Flathead, Lizard, Elkford East, Elkford West.

Wind slabs are expected to remain reactive to human triggering on Sunday.

It is also important to remember that a weakness exists at the base of the snowpack in parts of the region and very large deep persistent slab avalanches remain possible.

Confidence

High

Avalanche Summary

An early report from Saturday includes several natural and skier-triggered size 1 loose dry avalanches as well as a few small pockets of wind slab. Earlier in the week, a couple of bigger wind slabs were reported including this MIN post and this MIN post.

The deep persistent slab problem continues to be a concern for parts of the region. In the nearby Bull River area, this very large older avalanche was observed on Friday by the Avalanche Canada field team which is expected to have occurred on Wednesday.

Snowpack Summary

For the most part, the upper snowpack has been heavily altered by the wind and, on south aspects, the sun. That being said, opportunities to avoid lingering wind slabs and find softer snow still exist in sheltered, mostly north facing terrain features.

The middle of the snowpack is well consolidated and sits on a thick crust. The bottom of the snowpack still consists of weak, sugary crystals that are slowly gaining strength in areas with a deeper snowpack.

Deep persistent slab avalanches should still be on your radar in thinner snowpack areas outside of the Lizard Range such as the Bull River, Elkford, and the Flathead.

Weather Summary

Saturday night

Partly cloudy, possibly clearing by morning, light to moderate W-NW wind, treeline low around -10 ˚C.

Sunday

A mix of sun and cloud in the morning, cloudy in the afternoon with light flurries, moderate to strong SW-W wind, treeline high around -5 ˚C.

Monday

Snowfall beginning overnight 15-30 cm, moderate to strong SW-W wind, easing in the afternoon, treeline high around -6 ˚C.

Tuesday

Snowfall 15-30 cm overnight with another 5-15 cm during the day, moderate to strong SW wind switching to NE by the end of the day, treeline temperature dropping to around -20 ˚C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for areas of hard wind slab on alpine features.
  • Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

Problems

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.