Avalanche forecast

Cariboos

Sep 13, 2013 – Sep 13, 2014Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
No rating
Treeline
No rating
Below
No rating

Highlights

Daily forecasts will begin on Friday Nov 22nd, until then you have to act as your own forecaster. Here are some ideas to help you through the fall. And this should help if you’re wondering Where are the danger ratings?.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    Wind slab conditions will develop on lee terrain in exposed areas during storms or when the wind can pick up new snow and blow it around. Feeling dense surface snow or cracking around you helps alert you to these places.
  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–5
    The most prevalent (but possibly not the only) persistent weakness at this time of year will be facets that grow next to a crust, or at the interface between old snow/glacial ice from last season and this year?s new snow.
  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    Storm slabs are a problem during and immediately following storms producing more than 25 to 30 cm of new snow.

Confidence

Poor

Weather Forecast

Daily avalanche forecasts begin Friday Nov 22nd and we look forward to providing mountain weather forecasts once our season gets underway.

Avalanche Summary

The most likely early season problem you?ll have to deal with involves wind and storm slabs that are poorly bonded to the underlying snow. These are most dangerous during and immediately after a storm and are most commonly found in alpine bowls and in the lee of ridgelines. The danger can last much longer where slabs of this season?s snow overlie old patches of snow from last year, on sit on top of glacial ice. The reason is that bonds between last year?s snow and this year?s are often quite poor. Temperatures will typically fluctuate at this time of year, often bouncing above and below freezing. If you get a rapid spell of warming, or worse?rain, immediately after a good dump of snow, there?s a good chance of seeing an avalanche cycle. The consequences of being caught in an avalanche are heightened at this time of year, since trees, stumps and rocks litter runout zones. This is worth keeping in mind, as getting dragged through this kind of nastiness is definitely something to avoid.

Snowpack Summary

Successive early winter storms lead to a rapid buildup of the snowpack. Expect big changes to the snowpack structure with elevation, you might find full-on winter conditions in the Alpine and no coverage lower in the valleys. Here are some things to look for in the snowpack to help you identify potential avalanche danger. First, assess the quality of the slab. If the upper layers feel dense and show a tendency to crack or pull apart as a cohesive element, there?s a good chance conditions are primed for a slab avalanche. Watch the bowls below ridges and the gullies where there?s enough snow to slide. Second, try to identify areas where you might be riding over old snow from last year. These pockets often exist near the top of bowls, on the shaded side of steep gullies and under cliffs. Basically, they favour steep, high elevation north facing terrain. These pockets cause problems because the new snow from this year often bonds poorly to the old snow surface. This is particularly a problem where the new snow falls on steep glacial ice. Third, if you identify crusts within the snowpack, these can act as sliding layers, as well as promoting the growth of sugary facets above or below.

Regions covered