Avalanche Forecast

Archived

Jan 19th, 2014–Jan 20th, 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 unlikely, human triggered possible.

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

Glacier.

http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=15693&oPark=100205

Weather Forecast

A ridge of high pressure will remain in place for the foreseeable future. For the next three days expect alpine temperatures just below zero, with light ridge top winds and no precipitation.

Snowpack Summary

Over 1m of new snow from the last week is settling. It sits on a surface hoar/graupel layer. Strong SW winds have formed slabs in exposed terrain at all elevations. Expect to find a solar crust on steep SW/W aspects and a supportive rain crust below 1300m. The mid pack is well settled with the Nov28 surface hoar layer down around 2m where present.

Avalanche Summary

Avalanche control yesterday produced several size 1-1.5 avalanches in alpine terrain. 1 size 2 natural avalanche was observed from steep north facing terrain effecting the highway. All of these avalanches were east of Rogers Pass. Click on https://www.facebook.com/ParksMountainSafety to see images of the latest avalanche cycle this past Monday.

Confidence

Due to the number of field observations

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.