Mt Blackmore
Northern Gallatin
Code
HS-ACc-R3-D2-O
Elevation
8700
Aspect
E
Latitude
45.45640
Longitude
-111.01800
Notes
From an email:
We were still hesitant of our results from our snowpit so we decided to cut a cornice that would drop onto the slope below, which I'm estimating to be 40 degrees. We released a cornice that tumbled downslope. The cornice went roughly a quarter of the way downslope before triggering a hard slab avalanche that broke just below the corniced ridgline. The avalanche propagated on both sides of the path and propagated further downslope. The avalanche ran into the flats and flanked in two directions once the slope widened (which I've included in the map below).
We were unable to assess the crown in detail since we weren't comfortable with the amount of hangfire above, but estimate it to be 150 feet wide, running 1000 feet slope distance and roughly 600 vertical feet. The avalanche failed on the persistent weak layer interface that we had doubts about.
20200307 @ 12:30pm
Crown:
45.4626N, -111,0219W
8766'
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Cornice fall triggered by human or explosive action
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
3
D size
2
Bed Surface
O - Old snow
Problem Type
Wet Snow
Slab Thickness
24.0 inches
Vertical Fall
700ft
Slab Width
150.00ft
Images
Attached Videos
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year