Avalanche Forecast

Archived

Mar 26th, 2022–Mar 27th, 2022

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, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

North Rockies.

Warm air and rain may destabilize the snowpack at lower elevations, with new wind slabs potentially forming up high.

Adjust your travel plans accordingly to the changing conditions of elevation and time of day.

Confidence

Moderate - Uncertainty is due to rapidly fluctuating freezing levels.

Weather Forecast

SATURDAY NIGHT: Cloudy with light precipitation. 15-40km/h southwest winds. Freezing level dropping to 500 m.

SUNDAY: Cloudy with precipitation, 5-10 cm of new snow accumulation at higher elevations. 10-30 km/h southwest winds. Freezing level rising to 1800 m.

MONDAY: Cloudy with precipitation, 5-10 cm of new snow accumulation at higher elevations. 15-40 km/h northwest winds. Freezing level rising to 1500 m.

TUESDAY: Mainly clear. 10-30 km/h southwest winds. Freezing level rising to 2200 m.

Avalanche Summary

During the warm-up last week, widespread loose wet and wet slab avalanche activity occurred.

On Thursday, a natural wind slab (size 2) was observed in the alpine from southwest winds redistributing new snow.

Looking forward, riders may be able to trigger wind slabs in lee terrain features in the alpine and wet loose avalanches in steep terrain at treeline and below.

Snowpack Summary

Up to 15 cm of recent snowfall tapers rapidly with elevation. Southwest wind have formed small pockets of windslab in the alpine. A refrozen crust can be found below the new snow on all aspects as high as 2400 m. This crust is expected to break down throughout the day at low elevations with rain and warm temperatures. Below the crust, the top 10-30 cm of the snowpack is moist. At very low elevations, the snowpack may become wet and isothermal.

There are no deeper concerns at this time.

Terrain and Travel

Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Wind slabs may be poorly bonded to the underlying crust.
As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

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.

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.