Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Apr 8th, 2017–Apr 9th, 2017

Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.

Regions

Lizard-Flathead.

Cornices are the primary concern. Solar radiation is a common cornice trigger. Limit your exposure when it's cloudy and completely avoid cornices when it's sunny.

Confidence

High -

Weather Forecast

SUNDAY: Mix of sun and cloud with isolated flurries. Light southwesterly ridgetop winds. Freezing level around 1900 m.MONDAY: Mix of sun and cloud with isolated flurries. Light southwesterly ridgetop winds. Freezing level around 1700 m.TUESDAY: Mostly cloudy with flurries. Light southwesterly ridgetop winds. Freezing level around 1700 m.

Avalanche Summary

Numerous loose wet avalanches to size 1 in steep terrain were reported on Friday.

Snowpack Summary

10-15 cm of new snow and moderate southwesterly winds have created thin wind slabs on lee features below alpine ridgetops. Cornices are large, looming, and best avoided. The snowpack is well settled and continues to transition into a spring snowpack, becoming isothermal at treeline in some areas and below treeline in most areas. The December facets and November rain crust are buried deep, but these deep persistent weaknesses have not been reactive for several weeks. However, rapid warming of the snowpack or a large trigger, like a cornice, could trigger this layer.

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.

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.