Small avalanche on Sphinx Mountain

Sphinx Mountain
Northern Madison
Code
SS-AFc-R2-D1-O
Elevation
9500
Aspect
NE
Latitude
45.15820
Longitude
-111.47700
Notes

From Doug Chabot:

Today I turned around on the approach to an ice climb on the north face of the Sphinx. Cracking in the windblown snow was a sign of things to come. At the first wind-loaded gully I crawled on my hands and knees over to the slope and whacked it with my ice axe. It avalanched. Although it was only 4" thick, it propagated 75 feet above and scraped the snow over a cliff. We opted to not tempt any more slopes and went home.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Foot penetration
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
2
D size
1
Bed Surface
O - Old snow
Problem Type
Wind-Drifted Snow
Slab Thickness
4.0 inches
Vertical Fall
500ft
Slab Width
20.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year