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

Jan 18th, 2015–Jan 19th, 2015

Alpine
Natural and human triggered avalanches likely.
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

Little Yoho.

New snow combined with some intense winds and mild temperatures have formed new surface slabs. With the Dec 18 Persistent Weak Layer still a concern in this area be conservative and manage your exposure carefully. TH

Weather Forecast

The remains of Sunday's storm should play out early Monday morning and bring another 5 to 10 cm  as temperatures start to cool. Winds should also diminish around midnight but will likely remain in the moderate range at the treeline level. Expect a light snowfal (5 to 10cm) Monday with continued cooling into Tuesday before we may see some clearing.

Snowpack Summary

New windslabs are being formed in open lee areas treeline and above. The Dec 18 surface hoar layer is down 40-50 cm. This layer is very prominent and is producing moderate test results and lots of whumphing.  With up to 20cm of new snow in the last 72 hrs and another 5 to 10 expected Sunday and Monday morning, this layer may become active again.

Avalanche Summary

Skiers were able to easily trigger the sensitive new windslabs that have formed at Treeline and above today in neighboring areas. These  soft slabs propagated up to 20m and were up to 40cm deep. Poor visibility made it difficult to see further evidence of avalanche activity.

Confidence

Intensity of incoming weather systems is uncertain on Sunday

Problems

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.

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.

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.