Avalanche Forecast

Archived

Apr 19th, 2021–Apr 20th, 2021

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 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.

Below Treeline

Natural avalanches unlikely.

Regions

Cariboos.

The best and safest riding will be in north-facing terrain that is free from cornices overhead. Plan your day around avoiding sun-exposed slopes.

Confidence

Moderate - Uncertainty is due to rapidly fluctuating freezing levels.

Weather Forecast

Warm sunny weather continues until a weak frontal system arrives on Thursday.

TUESDAY NIGHT: Clear skies, light north wind, freezing level drops to 1000 m with treeline temperatures dropping to -5 C.

MONDAY: Sunny, light northwest wind, freezing level climbing to 2300 m with treeline temperatures reaching +2 C.

WEDNESDAY: Sunny with some clouds in the afternoon, light northwest wind, freezing level climbs to 2200 m with treeline temperatures reaching +2 C.

THURSDAY: Cloudy with scattered flurries bringing up to 5 cm of snow, moderate northeast wind, freezing level around 1400 m with treeline temperatures around -4 C.

Avalanche Summary

Although there are limited recent field observations, there have been enough to suggest there was a natural cycle of size 1-3 wet loose avalanches on sun-exposed slopes during a period of above freezing temperatures between Thursday and Saturday. There was also one report of a size 3 wet slab avalanche in the McBride area. See some photos in recent MIN reports here and here.

You can still expect wet loose avalanches and cornice falls on Tuesday, but they will be less widespread and destructive than they were over the weekend due to the relatively cooler temperatures.

Snowpack Summary

A surface crust will form overnight and then gradually break down with daytime warming. Dry snow may still be found in high north-facing terrain (above roughly 2300 m). While there have been no recent avalanches on buried weak layers, there are a few layers that could potentially be triggered during periods of with intense warming or a heavy cornice fall. This includes a few crusts buried over the last month as well as a 150 cm deep facet layer from the mid-February cold snap.

Terrain and Travel

Avoid exposure to steep sun exposed slopes.
When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Avoid lingering or regrouping in runout zones.

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.