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

Dec 10th, 2012–Dec 11th, 2012

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

Regions

Purcells.

Confidence

Fair - Intensity of incoming weather is uncertain on Tuesday

Weather Forecast

Overnight and Tuesday: A warm front is moving across the region tonight and a trailing cold front should move through the region in the morning. The West of the region may get up to 10 mm of precipitation starting early in the morning. Expect very strong westerly winds. The system may dry out quite a bit in the South and East (3-5 mm). Alpine temperatures -8.0 and freezing levels rising to 1000 metres.Wednesday: There is a weak ridge between systems that should bring light precipitation (3-5 mm), light Northerly winds and temperatures down to -12.0 in the alpine.Thursday: The next frontal system is looking weak at this time. Expect light precipitation and SW winds. Check back tomorrow for an update.

Avalanche Summary

No new avalanche activity reported.

Snowpack Summary

There has been a lot of unconsolidated surface snow (about 30-40 cms) that is now available for transport by the forecast strong Westerly winds. Expect wind slabs to develop in the alpine and at treeline. Heavy sluffing may continue to be experienced in sheltered locations. There is still concern about the weak surface hoar layer that is buried down about 100 cms; it may become reactive with the additional load of the new storm.

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.

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.