Avalanche Forecast

Archived

Mar 11th, 2017–Mar 12th, 2017

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Glacier.

Recent snowfall and rising temps will keep the hazard elevated over the next couple of days. Now is the time for conservative terrain choices!

Weather Forecast

Snowfall eases during the day today with 5 cms expected and freezing level rising to 1800m. Alpine highs of -3 are forecast with wind gusting to 40km/h from the south. More snow is on the way as a series of storms will bring precip and steadily increasing freezing levels into the middle of next week.

Snowpack Summary

Steady snowfall this week (plus another 15cm last night!) pushes our March total easily over 1m of new snow @ 1900m. The late Feb crusts are buried 50-100cm deep on solar aspects depending on elevation. A mixed form layer lies under the storm snow on north and east asps. The Nov Cr remains dormant while the midpack is gaining strength and rounding.

Avalanche Summary

Yesterday there was a widespread natural avalanche cycle to sz 4 on the highway corridor. These naturals were running full path & were triggered by rapid loading from heavy snowfall, avalanche activity will continue today. Friday there was a MCR & MIN post of sz 1 slab avalanches in the Connaught slide path & Little Sifton failing on the Feb Cr

Confidence

Timing, track, or intensity of incoming weather system is uncertain

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.