Avalanche Forecast

Archived

Apr 16th, 2022–Apr 17th, 2022

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

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

South Coast Inland.

Danger ratings are low, but always be on the lookout for wind slabs at higher elevations and weak overhanging cornices.

Watch for strong sunshine creating wet surface snow on south facing terrain features.

Confidence

Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack. Uncertainty is due to the fact that cornice falls are particularly difficult to forecast.

Weather Forecast

SATURDAY NIGHT: Cloudy with light southeasterly winds. 2-5 cm of snow expected. Freezing levels drop to 500 m.

SUNDAY: A mix of sun and cloud with light southerly winds. Freezing levels rise to 1500 m. Isolated flurries are expected to bring trace amounts.

MONDAY: Light snowfall over the day, up to 5 cm. Freezing levels reach 1500 m. Strong southerly winds. Snow continues overnight with up to 10 cm expected.

TUESDAY: Cloudy with continued light snowfall bringing up to 10 cm over the day. Freezing levels reach 1200 m. Moderate to strong southerly winds.

Avalanche Summary

Several size 1-2 wet avalanches have been reported over the last 3 days, from strong sunshine.

On Thursday a natural cornice fall was observed, that did not trigger an avalanche on the slope below. Further details are unknown. On Tuesday, size 1 and 2 natural and skier triggered wind slab avalanches were reported. These occurred at higher elevations on west facing slopes from the recent easterly winds.

Snowpack Summary

10 to 30 cm of dry, wind-affected snow sits above a crust or hard surfaces at higher elevations. Small wind slabs may be found at high elevations from recent easterly winds. A melt freeze crust likely sits on the surface at lower elevations and on sun affected slopes. Periods of sun may soften or break down the crust throughout the day.

Various melt-freeze crusts exist in the upper to middle snowpack, which reports suggest are bonding well. The lower snowpack is considered strong and well settled at this time.

Terrain and Travel

Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet

Problems

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.

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.