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 13th, 2012–Apr 14th, 2012

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

Regions

South Coast.

Confidence

Fair - Freezing levels are uncertain for the entire period

Weather Forecast

Saturday: A mix of sun and cloud. Freezing level around 1700 m. Minimal wind.Sunday: Warm and dry, with increasing cloud and winds increasing from the SW in the afternoon. Freezing level around 1600 m. Monday: Light to moderate precipitation, mostly falling in the early morning. Moderate SW winds. Freezing level around 1600 m.

Avalanche Summary

Recent reports include cornice fall and loose wet avalanches. Full-depth size 2-3 glide avalanches have been releasing on rock slabs.

Snowpack Summary

Rain fell to 2000 m on Wednesday. Ongoing warm temperatures and the rain have caused the surface snowpack layers to become isothermal (at 0 °C), even on north aspects, to about 2100 m. This is expected to have formed a crust in most areas, now covered by a small amount of new snow. Very large cornices are looming. Glide cracks have opened up and pose the threat of large, full-depth releases, especially on steep rocky terrain features at low elevations. Otherwise, a relatively strong and deep spring snowpack exists, which becomes weak during periods of warm weather or rainfall. A buried crust/surface hoar layer from late March, within the upper 1.5 m of the snowpack, is reported to have gained strength in the Duffey Lake area, but remains a lingering concern.

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.

Wet Slabs

Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.