[MCR] Rockies - Mistaya Lodge - large avalanche cycle

[Public Mountain Conditions Report]

A beautiful day for observations with the ACC / The North Face winter
leadership course today revealed some eye opening avalanche activity. Had a
large cycle of natural avalanche activity in the last 12 to 24 hours where
we saw numerous (more than 20) avalanches from Size 1 to Size 3.5 on all
aspects at elevations from 2000 to 2600m (many size 2.0 to 2.5). Slope
angles ranged from 30 to 55 degrees. Crowns were typically 100 to 150 cm
with some up to 200 cm. Several avalanches observed were in unusual
locations.

Winds and cooling temperatures immediately preceded this wide spread cycle.
Several step down avalanches were observed on East aspects where the bed
surface was ground or the November rain crust.

The Size 3.5 natural avalanche off of the Baker Glacier (Sabretooth run) ran
from 2700m down to 2280m. It hit the lake below, blasted the ice out of the
lake and piled everything up on the opposite shore (quite a devastating
sight!)

We had well over 100 cm of storm snow in the storm which ended a day ago.
The storm snow has now settled out to 75 cm. The day before in our study
plot at the lodge we had foot penetration of 135 cm whereas it is now only
65 cm. Similarly we found ski penetration went from mid thigh to boot top or
less in open areas. There was a lot of wind affect in all open areas at and
above treeline (limited observations below treeline). Plenty of slab
formation with wind still transporting snow throughout the day.

Dave Birnie ACMG SG
Mistaya Lodge

Cyril Shokoples ACMG MG
Rescue Dynamics

And the crew of the ACC / TNF course