Fall and Early Winter Avalanche Hazards
Originally prepared for Avalanche-Center.org.
Fall and early winter do not see as many avalanche incidents as
mid-winter or spring, but several are reported each year with one
or two typically involving fatalities. It seems that many of the
victims are simply not thinking about the potential, either because
they generally travel in winter after there is more snow
or because they think there is not yet enough snow to constitute
Frequently the people who get caught earliest in the season are not
winter recreationalists but hikers, hunters, or others not accustomed
to considering avalanche risks and terrain features conducive to avalanches.
of 1998 a group of hikers was caught in the Canadian Rockies. The
same month a
hunter died in an avalanche in Montana where wind sheltered slopes
at the time had only 14 inches of snow. In November
of 1997 two would-be skiers decided to hike due to a lack of snow.
One of them ended up dying in an avalanche.
These avalanche incidents which occur earliest in the season usually
result from an underlying assumption that there is not enough snow
yet for an avalanche to occur. Snowfall is redistributed by wind,
and some areas may have enough snow to slide even when adjacent
ground is bare. The areas most likely to present a problem are gullies
and steep high slopes which are shaded. Both of these features,
if oriented so that the wind fills them with snow, can be hazardous.
Gullies can often present additional hazards, worsening the potential
consequences of a slide. Watch out for snow filled features which
lie above rock bands and/or feed into steep sided areas like creek
beds where the accumulation of sliding snow could be deep. It is
often possible to avoid the potential hazard by a short detour around
the terrain feature. When that is not possible it is best to use
standard avalanche terrain travel practices, especially crossing
the area one at a time with somebody watching the person crossing.
As the winter progresses the most avid skiers and snowboarders
begin to encounter avalanches. Many times in the earliest season
skiing/boarding incidents the victims had to walk to get to a location
with enough snow to ski or board. This leaves them with the impression
that there is not enough snow to worry about avalanches. The very
slopes these people seek for skiing or snowboarding are the ones
which have been loaded by the winds - that's why the snow is there.
In areas with a cold climate the earliest snow to accumulate in
shaded areas can sometimes turn into weak sugary crystals called
depth-hoar. New snow deposited on top of these crystals will be
poorly supported. Skiers and snowboarders seeking early season pockets
of snow should be able to assess the snowpack on their own, an avalanche
advisory is unlikely to be available. They should also take the
same precautions and carry the same safety equipment as they would
later in the winter.
Finally, there are sometimes close calls every year inside ski area
boundaries before the area is open. Remember that prior to opening
ski areas are neither controlled nor patrolled and are essentially
backcountry. All risk is yours - travel accordingly!