Lawine

Hellroaring Peak

blase reardonWhitefish Range
Auf der Karte ansehen
Beobachtungsfoto 1

Quick report

Cracking
isolated

W investigated the terrain north and west of WMR, looking for the Persistent Slab structure identified last week in the terrain to the east. 

  • The forecast for fluff did not materialize. 4+ inches of new snow by midafternoon, but it was more like 10%  density than 5%. Hardly a dendrite in sight. 
  • We triggered one small soft slab avalanche that involved just the new snow, though it seemed to propagate widely. 
  • One ridgeline drift cracked but did not move. 
  • We only found a distinct persistent slab structure on a southwest facing slope at 6600 feet. It was not reactive in tests, though the weak layer was obvious.
Limited cracking, mostly just short (< 0.5 m) around skis. One drift at a ridgeline cracked when I stepped on and started to slide, though it didn't move more than a few inches. 1 triggered soft slab avalanche (See avalanche tab)

Weather

Air Temp
14
Cloud Cover
obscured
Wind Loading
previous
Recent Snowfall
10
Snow Avail For Transport
moderate amounts

Continuous S1 from late morning to mid afternoon. Intensity seemed to pick up then, though it didn't seem to hit S2. Winds calm.

Snowpack

Dug on ENE (6700 ft),  NW (6600 ft) and SW (6600 ft). We were surprised to only find a Persistent Slab structure on the SW slope, where the snowpack was shallowest.

  • The weak layer is large-grained (3-4mm) depth hoar sandwiched between two crusts (12/22 below and 12/31? above). 
  • This is essentially the same structure we found in a crown profile at 6150 ft on a SW slope oon 1/8. 
  • Despite the depth hoar falling out of the pit face, it did not fail in an ECT. It did fail as we isolated a smaller column for a Compression Test.
  • This profile was the only place where the underlying 12/22 crust was pencil hard. 

In the other two profiles, we were surprised at how soft and degraded the early season crusts have become. We found small facets above and below the 12/31 crust on the ENE profile. but these did not propagate in a test (ECTN28 above 12/31 crust). 

 

Avalanche

Size
D1 R2
Type
SS
Aspect
SE
Trigger
AS
Elevation
6300 ft

Triggered a thin soft slab avalanche when I stopped above a steep road cut. No results on similar slopes.