Avalanche Forecast

Archived

Apr 8th, 2025–Apr 9th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

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 unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Lizard-Flathead, Flathead, Lizard, Crawford, Moyie, St. Mary.

730 am UPDATE: If you see over 20 cm of new snow, dangerous storms slabs are likely, so step back to simple terrain.

Confidence

Moderate

Avalanche Summary

Over the weekend, small wet loose avalanches were reported to size 1.

Riders may be able to trigger slabs in areas with more than 20 cm of new snow, especially deeper areas lee to the wind. While at lower elevations, rain soaked snow may lose cohesion and fail as wet loose avalanches.

Snowpack Summary

Up to 20 cm of snow fell at higher elevations on Tuesday, with more on the way. This snow is on either a crust up high, or moist snow down low. At lower elevations, the new snow may have fallen as rain and made the upper pack wet and loose. There are currently no deeper layers of concern.

Weather Summary

Tuesday Night

Cloudy with 5 to 15 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1500 m.

Wednesday

Cloudy with 0 to 2 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 2000 m.

Thursday

Mostly sunny. 20 to 30 km/h southwest ridgetop winds. Treeline temperature +3 °C. Freezing level 2800 m.

Friday

Cloudy with 5 to 15 cm/mm of snow/rain. 20 to 40 km/h southwest ridgetop wind. Treeline temperature +1 °C. Freezing level 2000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Continue to make conservative terrain choices while the storm snow settles and stabilizes.
A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.
Cornices often break further back than expected; give them a wide berth when traveling on ridgetops.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

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.