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

Apr 17th, 2015–Apr 18th, 2015

Alpine
Below Threshold.
Treeline
Below Threshold.
Below Treeline
Below Threshold.
Alpine
Below Threshold.
Treeline
Below Threshold.
Below Treeline
Below Threshold.
Alpine
Below Threshold.
Treeline
Below Threshold.
Below Treeline
Below Threshold.

Regions

Little Yoho.

We are gradually moving into true spring melt- freeze conditions although higher N facing terrain still has a winter snowpack. Start early, minimize exposure to steep solar aspects later in the afternoon, and enjoy the fast travel.

Weather Forecast

Winds are forecast to switch to the North and calm down on Friday night as a ridge of high pressure begins to build. No new precipitation is expected on Saturday or Sunday. Freezing levels should start at valley bottom overnight but rise to 2100m on Saturday and 2200m on Sunday. Early starts and finishes will be important.

Snowpack Summary

Moist snow up to 2100m on all aspects and to ridge top on all solar aspects. Lots of wind effect in alpine areas. Recent wind slabs are beginning to bond but may still be an issue at higher elevations. Cornices are a major concern with the winds and warm temperatures. Recent cornice failures have triggered the basal facets in thin snowpack areas.

Avalanche Summary

Wet loose natural avalanches up to size 2 were seen Friday afternoon with the warm temperatures. Isolated whumpfing was still noted in the Observation Sub Peak area Thursday and was likely due to new wind slabs sitting over sun crust. On Wednesday, a large cornice release triggered a size 3 avalanche on the basal facets in the Sunshine backcountry.

Confidence

Problems

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.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

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.