Kathy, Will and I spent Dec 29-31 wandering about the Wapta Icefield.
Over the trip winds were generally moderate from the west, with strong
winds at ridgetops on Dec 30. Moderate snow transport at ridgetop most
of the time. Max of -6 at Bow Lake Dec 29, minimum -15 at Olive/St Nick
col Dec 29. -9.5 at Bow Hut the morning of Dec 31. Regular flurries
left a few cm of new snow over the trip. Visibility varied from
obscured to broken.
Approach to Bow Hut is as per my post for Little Crowfoot a few days
ago. Up on the ice we saw about 2 m of snow at around 2700 m at the
head of the Bow Glacier, with deeper snowpacks at higher elevations in
sheltered areas. The light was never very good but it seemed that the
icefield was quite smooth with few visible crevasses. Ski penetration
was generally ankle deep, minimal wind effect in the most recent
snowfalls although with probing it seemed there was a 40cm thick wind
slab atop a thin weakness, beneath the 10-15cm soft surface snow
layers. Cornices are large.
On the 30th poor visibility, loading winds, occasionally intense
flurries, suspected large cornices and unknown crevasse difficulties
created too many "ifs" for us to go from Balfour Hut over the Balfour
High Col to Scott Duncan. I like to have good visibility or a Low to
Moderate Danger rating (or, better yet, both) to consider committing to
that place. We had neither so we climbed Olive on the way back to Bow
that day.
Good skiing on the Bow Glacier on Dec 30 and 31. Lots of people though.
The only avalanche activity we saw was exiting on Dec 31. A large size
2 had run sometime in the previous 24 hours in the path beyond the end
of Bow Lake, on the south flank of Mt Jimmy Simpson. It came out of
steep, unskiable cliffs and gullies to the right of the waterfalls. It
was a slab, about 40cm thick, initiating on a steep slope in the lee of
a ridge at treeline and cleaning out the cliffs below. It ran about 2/3
of the fan in the runout zone.
I'm also pretty sure I heard a sizeable avalanche off Olive during the
wind event of Dec 30, but couldn't see it in poor visibility.
I rated the Danger as Considerable in the alpine and treeline and Low
below treeline, throughout the trip.
Mark Klassen
Mountain Guide
mark@xxxxxxxxxxxx
www.alpinism.com
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