After a bit of a sunny break today, unsettled weather is forecast to move in bringing cooler and wetter conditions to the northern and central areas of the Rockies and Columbia mountains over the weekend, especially at higher elevations. Southern and eastern regions will stay drier and warmer, but there is potential for strong winds up high throughout the weekend in most areas.
The last week has been a mixed bag of weather with some new snow at higher elevations and strong winds over the past couple days. Snowline in the main ranges of the Rockies is down to treeline or about 2300 m. 5 cm of new snow was reported yesterday in the Lake O'Hara area with icy trails at upper elevations. On the glaciers in the Lake Louise, Wapta and Columbia Icefield areas, up to 60 cm of settled snow has been reported at higher elevations and some recent wind loading has been observed. The eastern ranges of the Rockies have significantly less accumulated snow, but there is still a dusting of snow in most areas at higher elevations and on shaded aspects above treeline making for slippery travel in many locations.
Web cams in Rogers Pass, Revelstoke and as far south as Nelson also show a dusting of recent snow down to treeline although there is less accumulated snow at upper elevations as you go further south. The snowpack on the glaciers in the Columbia mountains is starting to accumulate and form the base of the winter snowpack and you can expect similar amounts to what has been seen in the Rockies.
The main mountain hazards right now involve thinly bridged crevasses, isolated pockets of wind slab, and verglass/snow covered rock at upper elevations.
Winds and new snow over the past few days have helped form thin, weak crevasse bridges. This is coupled with the increased amount of open crevasses at higher elevations after a hot dry summer. Careful route finding with lots of probing and a taut rope will be important for any glacier travel, and expect travel to take longer and be more complicated than in some previous years. The occasional skier has been out on low angled glacier terrain but there are very limited places where this could work. If you do need to go, be very wary of any crevasses you encounter and watch for thinly covered rocks.
The recent winds have also created some pockets of wind slab in the high alpine so assessing the avalanche hazard in loaded areas will need to be part of the decision making process going forward. Even small slabs could have serious consequences with thinly covered rocks in the runout zones. Consider dusting off the avalanche gear if it's appropriate.
I have not heard of any climbable ice drips yet, but they will be forming soon. In the meantime expect a fair bit of verglass and snow covered rock in the alpine especially on shaded aspects. Bring the appropriate equipment to deal with this on scrambles, climbs or hikes as needed (good boots, cleats, ski poles, crampons, ice axe, etc).
The current conditions should lead to the formation of some alpine ice and good mixed climbing conditions in select spots if the weather cooperates. Timing the conditions will be key to making things work and and this point the forecast doesn't quite look ideal for the next week.
The best bets will be alpine rock climbs and scrambles on solar aspects in the eastern and southern areas of the Rockies and Columbia mountains, lower elevation rock climbs, and straightforward glacier travel routes that allow for good options to move carefully through the crevasses.
Don't forget to bring extra clothing and fully charged headlamps as the days get shorter and cooler. On an alpine rock route in the front ranges two days ago we wore every stich of clothing we brought for the entire route and would have been happy with more.
Enjoy the stunning fall colors where ever you end up and have a good week!
ACMG Mountain Guide