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 12th, 2014–Mar 13th, 2014

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

Regions

South Rockies.

Rain soaked and moist upper elevation snow packs may take a while to cool off and stabilize. Pay close attention to daytime heating and mature cornices. For more information on the tricky conditions see the latest:Forecasters Blog:

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

Synopsis: The ridge of high pressure holds for the next few days with clear skies and warm spring-like conditions. There is a possibility of moisture by the weekend.Tonight: Clear periods, freezing level will drop to valley bottom. ridge top winds light, occasionally gusting to strong from the west.Thursday: Sunny with cloudy periods, freezing level around 1400m. Light ridge top winds occasionally gusting to moderate.Friday: Cloudy with sunny periods, light to locally moderate precipitation amounts, freezing level around 1400 metres, winds from the southwest , light to moderate, occasionally gusting to strong.Saturday: Cloudy with scattered flurries. freezing level around 1400 metres, ridge top winds light, occasionally gusting to strong.

Avalanche Summary

No reports of avalanches in the forecast region from yesterday, but a neighboring region had a large, wet avalanche that ran full path between 2100m and 1700m. on a west aspect.. Cornices have gotten large and mature and may trigger large destructive avalanches if they fail. There have been two reports recently where human triggered avalanches were initiated from roads below clear-cuts and ran full path with destructive consequences. Daytime heating and nighttime cooling are a critical part of the daily hazard evaluation. Cut blocks, road cuts, and low angle terrain should be considered as possible start zones for avalanches during this warm period..

Snowpack Summary

Night time cooling will help to stabilize the tricky conditions as the storm slab settles and gains strength, although freezing levels are forecast to be up into the 1400 to 1600m range. Below that elevation there will be no overnight freeze and recovery of the snow pack. In some parts of the region, the snowpack is isothermal and saturated with water below 1600 metres. Any disturbance could trigger a wet dense avalanche on this type of snow. Above 1600m the previously mentioned weak layers still exist, especially on north aspects. Slopes gaining heat from the generally rising temperatures and strong spring sun should be highly suspect,.. and treated with respect and caution. The weak layers buried in this years snow pack are not going away soon, and may not go away until the seasons snow has completely melted, especially on north aspects

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.

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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.