Avalanche Forecast

Archived

Apr 22nd, 2021–Apr 23rd, 2021

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.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Northwest Inland.

Stay alert to changing conditions during the heat of the day and adjust your travel plans accordingly. Back off slopes if the surface becomes moist or wet with daytime warming.

Confidence

High -

Weather Forecast

THURSDAY NIGHT: Clear / Light, northwest ridgetop wind / alpine low temperature -7 / Freezing level valley bottom.

FRIDAY: Mostly sunny / Light, west ridgetop wind / alpine high temperature 3 / Freezing level 1500 m.

SATURDAY: Mostly sunny / Light, east ridgetop wind / alpine high temperature 2 / Freezing level 1400 m.

SUNDAY: Sunny / Light, east ridgetop wind / alpine high temperature 3 / Freezing level 1500 m.

Avalanche Summary

One naturally triggered size 2 wet loose avalanche was reported on a southwest aspect in this region on Wednesday.

NOTE: Observations are very limited during this time of year.

Snowpack Summary

The snowpack has been undergoing a melt-freeze cycle with successive days of warm sunny weather. Strong solar radiation and warming can initiate wet loose avalanches as the snow loses cohesion. Cornices are large and looming along ridgelines. Sun and warm temperatures can increase the chances of cornice failures, especially when temperatures remain above zero overnight. Check out the Forecaster's Blog for information on how to manage these spring conditions.

The snowpack is overall strong and settled in most areas, however, sustained warming can increase the likelihood of large avalanches failing on deeply buried weak layers. This is most likely to occur on steep, rocky alpine slopes with a shallow or thin to thick snowpack.

Terrain and Travel

As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
Back off slopes as the surface becomes moist or wet with rising temperatures.

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.