Avalanche Forecast

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For daily mountain weather forecasts visit: http://www.avalanche.ca/weather

Common early season avalanche problems include wind slabs and storm slabs which typically present the biggest hazard during and immediately after storms or after significant winds. These early season slabs occur most readily where early season riding is good, that is where the underlying ground is smooth in places like grassy slopes, rock slabs, or glaciers. If there is enough snow to ride without hitting rocks or logs, there is enough snow for avalanches. Significant temperature fluctuations are common at this time of year, often bouncing above and below freezing. If you get a rapid spell of warming or rain after a good dump of snow, there's a good chance an avalanche cycle will occur. The consequences of being caught in an avalanche are heightened at this time of year, since trees, stumps, and rocks are still exposed. Terrain traps are more pronounced and it is advisable to minimize exposure to gullies, open water, cliffs, and rapid transitions from steep to flat where the consequences of even a small avalanche can be severe. Ice climbs with terrain above require careful planning and should be treated as avalanche terrain when there is potential for even small slides from above.

Expect big changes to the snowpack structure with altitude; you might find full-on winter conditions in the alpine, rugged travel at treeline, and no coverage at lower elevations. The early season snowpack evolves rapidly especially if it is snowing and blowing; be prepared for major changes in conditions from day to day. Here are some things to look for in the snowpack to help 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, conditions may be primed for a slab avalanche. Watch the bowls below ridges, gullies, and lee slopes where snow tends to accumulate deep enough to slide. Second, new snow from this year often bonds poorly to pockets of last year’s snow that survived the summer. These pockets are often found near the top of bowls, on the shaded side of steep gullies, under cliffs, on glaciers, and in high elevation, leeward terrain. Third, crusts are common in early season new snow often bonds poorly to these crusts. If you see or feel crusts, check the bond of overlying snow, especially if loose, sugary facetted grains lie above or below the crust.