It is that time of year again to start up the MCR summary machine, and we will keep it running through the summer and into the late fall.
Avalanches and cornice collapses in all regions are still the biggest hazards during this transition period, and should be monitored as conditions vary dramatically through the day. Avalanche gear while skiing or climbing should still be worn in avalanche terrain that still has snow on it, even though our minds are shifting to summer.
This past week has been wintery in the west, with overnight lows in the alpine nearing -20°C and little storms bringing in small but constant amounts of snow in the Rockies and Columbia mountain ranges. In the Rockies, treeline snow depths are now above threshold for avalanches (50 cm+) and in the Rogers Pass area you can expect up to double that. Alpine snow depths are over a meter in the Rockies and over 150 cm around Rogers Pass.
Another beautiful autumn week in the Rockies and Interior BC, but looks like we're returning to a more typical colder weather pattern in the days to come. If snowfall amounts in the high Rockies and further west are substantial we will be back to early winter mode again with avalanche concerns rising back to the top of our list of hazards for mountain travel.
The keen interest everyone had in skiing last week has precictably tapered off with the drier weather this week. Warmer temperatures and wind have resulted in not the most enticing snowpack for even diehard skiers.
The long range forecast calls for more dry weather across western Canada into next week with rising temperatures. Clear skies and overnight lows in the alpine of well below freezing (possibly down to -15 C), however, mean that mixed alpine and even ice climbing could be coming into good condition very soon.
Winter arrived on the East slope of the Rockies with a bang on Tuesday. Snowfall was from 20-40cm depending up on location and it tapered slightly as you went west. Very little wind observed with the storm but as is usual for this time of year we have very few observations from treeline and the alpine during storms. It would be a safe assumption that there has been some wind effect in the alpine and dramatic solar radiation effects on S and W aspects at least today.
September hasn’t been typical, and this last week was a very snowy one. In the Rockies there were reports of more natural avalanches up to 2.5 (maybe larger) in the Louise group with deeper than normal fracture lines of up to 1.5meters on lee aspects. The Silverhorn avalanche reported last week that was triggered by climbers (size 3) was completely filled in today as I drove past the Columbia Icefields. There are reports of up to 1m of storm snow that has drifted deeper in certain features, and alpine travel has been “futile” according to a few reputable sources.
It may not be winter yet but it sure feels more like October 20th than September 20th. The first major avalanche involvement of the season occurred on Mt Athabasca yesterday and it looked like a wild ride and a very close call. Also a couple of other slab avalanches were observed failing on glacial ice in the past 2 days. At this point we certainly don't have the observations to be able to say if this avalanche problem will persist for awhile but I would certainly be very gentle in my glaciated terrain choices till we know something has actually changed.