Strong solar radiation and high daytime freezing levels are expected to elevate the avalanche danger. Avoid slopes that are exposed to overhead cornices.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain on Friday
Weather Forecast
Overnight: Overcast with 5-10 cm of new snow and moderate-strong northeast winds. Freezing down to 1300 metres by morning. Friday: Mostly clear with strong solar radiation and winds switching to the west. Daytime freezing levels up to at least 2300 metres. Saturday: Mix of sun and cloud with strong westerly winds, and little or no re-freeze below 2300 metres. Sunday: Overcast with light westerly winds and daytime freezing around 1800 metres.
Avalanche Summary
No new avalanches reported.
Snowpack Summary
On Thursday in Crowsnest North, the sun was strong in the morning and solar aspects became moist up into the alpine. There was still some dry snow on north aspects in the alpine. A few more cm of new snow overnight, combined with gusty southwest winds has developed new wind slabs in the alpine and at treeline. The bottom third of the snowpack is composed of weak facets and full-depth avalanches over this basal weakness remain a concern, and may be triggered by large loads like cornice falls, or strong solar radiation on a clear day.
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.
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.