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

Mar 30th, 2013–Mar 31st, 2013

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

Regions

Northwest Inland.

Be alert to conditions that change with daytime warming. Danger ratings may exceed posted levels when solar radiation is strong.

Confidence

Good

Weather Forecast

Clear skies are expected on Sunday with increased cloud on Monday and a chance of light precipitation on Tuesday. Winds will be mostly light from the southwest increasing to moderate late Monday. Freezing levels may reach 2400m on Sunday, 1800m on Monday and then 1400m on Tuesday.

Avalanche Summary

Numerous loose wet avalanches have occurred from steeper solar aspects up to size 2.0. Size 2 cornice releases have also been noted. A size 2 natural slab avalanche was also reported in Morning Bowl in the Hankin area. It reportedly failed down to rocks in shallow places on a convex roll. I would expect more of this activity with forecast warming.

Snowpack Summary

Surface snow has settled with the influence of warm temperatures and surface hoar is growing on shaded slopes. Solar aspects and lower elevation terrain are now well into a daily melt-freeze cycle with sun-exposed slopes becoming very weak with daytime warming. 30 - 60 cm of snow overlies a crust, old wind slabs or surface hoar layer buried on March 9th. Reports suggest this layer is less reactive, but may still be a concern in some areas. The distribution of the surface hoar is also highly variable and it may not exist in every drainage. I would still remain conservative and continue to dig and test before diving into my line. Deeper in the snowpack, basal facets may resurface as a concern with forecast warming.Cornices have become well-developed and could easily become unstable during periods of warm weather or direct solar radiation.

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.

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.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.