23-24

Recent instability in the new and wind drifted snow

CENTENNIAL RANGE
Island Park
Code
SS-N-R2-D2-I
Aspect Range
N-E-S
Latitude
44.54890
Longitude
-111.73100
Notes

Two rider-triggered avalanches near Reas Peak on north aspects that broke within or just below the new storm snow (D1s)

Natural avalanche broke near Yale Creek on a southern aspect that broke below new snow (D1)

Two natural avalanches that broke within the wind drifted snow in Jefferson Bowl (D2s)

Number of slides
5
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
I - Interface between new and old snow
Problem Type
Wind-Drifted Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Collapse Near the Sphinx

Sphinx Mountain
Northern Madison
Code
Latitude
45.15820
Longitude
-111.47700
Notes

From email: We were out camping around the east side of Sphinx Mountain. We rode sleds over dirt for a while and came from Buck Ridge. We didn’t see any fresh avalanche crowns all weekend. We did get a big whoomph that collapsed the snowpack while skinning along a ridgeline on Sphinx that seemed freshly loaded. Cracks shot out maybe 25 feet around, but it didn’t move. We didn’t dig snow pits; we followed our plan of keeping our terrain selection on the mellow side.

Number of slides
0
Number caught
0
Number buried
0
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Red Flag
Advisory Year

Collapse Near the Sphinx

Date
Activity
Snowboarding

From email: We were out camping around the east side of Sphinx Mountain. We rode sleds over dirt for a while and came from Buck Ridge. We didn’t see any fresh avalanche crowns all weekend. We did get a big whoomph that collapsed the snowpack while skinning along a ridgeline on Sphinx that seemed freshly loaded. Cracks shot out maybe 25 feet around, but it didn’t move. We didn’t dig snow pits; we followed our plan of keeping our terrain selection on the mellow side.

Region
Northern Madison
Location (from list)
Sphinx Mountain
Observer Name
Tom Grande