Widespread whumpfing/collapsing and cracking above Hebgen Lake

Hebgen Lake
Lionhead Range
Aspect Range

Observation 1:

Sun 1/3: Skied both north and east facing terrain on the west side of Hebgen today. The few inches of new snow that has fallen recently seemed a bit denser than what was already on the ground. Made for an EXTREMELY touchy day. Widespread whumpfing and collapsing everywhere we went. We kept our slope angles low. On one slope we had a large collapse when the first skier started which created many longitudinal cracks across the entire width and length of the slope. We measured the slope at 27 degrees - I am confident a steeper slope in this area would have easily released.

Observation 2:

Summary of observations from Sat 1/2 and Sun 1/3: -No avalanches observed -Lots of whumphing and shooting cracks on N through SE aspects between 6600' and 8900' -3" of new snow at 8900' within 24 hour period from Saturday to Sunday; snowed S1 for a few hours Sunday morning but stopped by 1 p.m. and skies went from obscured at 9:00 a.m. to broken at 3:00 p.m. -Imperceptibly calm winds on Sunday below ridgetop at 8900' and trees holding snow at all elevations; ridge at 8900' had light Westerly winds gusting at moderate; we observed blowing and drifting snow at ridgetop being deposited on NE through E slopes. Snowpit Data from E aspect at 8200' (26 degree slope) on Saturday 1/2 at 1:00 pm: HS 75cm Weakest layer found at 50 cm down; weak layer is the interface between F-hardness basal facets (2-3mm) and 4-F, smaller facets above them Test results on this layer were ECTPV, ECTP13, and PST 25/100 (end)

Number of slides
Number caught
Number buried
Problem Type
Persistent Weak Layer
Slab Thickness units
Single / Multiple / Red Flag
Red Flag
Advisory Year