May 30, 2008
The May 24th weekend saw a significant storm in the upslope areas of the
Rockies. Canmore received upwards of 50 mm of rain at valley bottom
elevations and a good dump of storm snow above 2000 m. Precipitation
amounts dissipated rapidly the closer you got to the Continental Divide.
The storm amounted to rain and snow showers in the Columbia Icefields with
only five to ten cm of snow accumulation at upper elevations.
Warm daytime temperatures over the last couple of days have resulted in
afternoon loose snow avalanches and some slab avalanches in the recent
storm snow.
Currently in the Rockies very little snow remains at the below treeline
level, but in the alpine a higher then average snow pack remains for this
time of year. Reports from the Columbia Icefields state generally good
travel conditions in the morning, with the surface snow becoming slushy at
lower elevations in the afternoon. There is an unsupportive melt freeze
crust at higher elevations that makes travel a bit frustrating for those of
you on foot.
In the alpine along the Continental Divide spring time avalanche conditions
exist. As long as we are continuing to get the warm sunny days and the
cooler nights the avalanche hazard can range from low in the morning, to
high in the afternoon when the snow pack begins to warm up. The persistent
weak basal layers that have dominated this winters snow pack create the
potential for full depth slab avalanches when things really warm up. This
is evident from all the deep fracture lines that still can be seen from the
warm weather earlier in the month. Pay particular attention to being on or
under big alpine slopes during the heat of the afternoon.
In Banff and the east slopes of the Rockies conditions for rock climbing
are excellent with even the north facing crags beginning to dry out.
The forecast is calling for possible afternoon thundershowers for the
weekend, so keep your eyes open for the building cumulus clouds.
Brian Webster
ACMG/IFMGA
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These observations and opinions are those of the person who submitted them. The ACMG and its members take no responsibility for errors, omissions, or lapses in continuity. Conditions differ greatly over time and space due to the variable nature of mountain weather and terrain. Application of this information provides no guarantee of increased safety. Do not use the Mountain Conditions Report as the sole factor in planning trips or making decisions in the field.
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