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

Feb 17th, 2017–Feb 18th, 2017

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.
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.

http://www.pc.gc.ca/apps/links/goto_e.asp?destination=

Potential for large avalanches persist. Conservative route choices remain the theme of the day. Ice climbers should pay attention to freezing levels and adjust their route choices accordingly.

Weather Forecast

Saturday will be mainly cloudy with some isolated flurries. Freezing levels will drop to near surface friday night and climb up to 1500 m for Saturday through to Sunday, with light south wind and flurries continuing through the weekend. 

Snowpack Summary

40-60 cm of snow in the past week combined with mod SW winds created new reactive windslabs on lee and crossloaded features. This rests on hard windslabs which overlie a structurally weak mid-pack. Test results show sudden planner failures in the storm snow & persistent mid pack facets. Below 1800 m the snowpack is moist from rain event on Thur.

Avalanche Summary

Several avalanches in the BYK region in the past 24 hrs, some stepping down to deep persistent layers and the ground. Warm temps and rain below 1800m in Field on Thursday triggered a loose wet avalanche cycle at lower elevations. Avalanches up to size two were observed running over several of the ice climbs on Mt Dennis.

Confidence

Freezing levels are uncertain

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.