Observation: Public
Observation Details
Name:
Andrew KieferObservation Date:
March 26, 2021Submitted:
March 26, 2021Zone or Region:
West NorthActivity:
Snowmobiling/SnowbikingLocation:
Canyon CreekObserved Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Soft SlabSize:
Size 1: Relatively harmless to peopleElevation:
5600Aspect:
NEComments:
A recent natural slab avalanche (D1.5) at 5600ft on the northeast aspect of Bearpaw Mountain. The avalanche may have been triggered by sluffing or cornice fall and was 40ft wide and up to 1ft thick. The avalanche occurred sometime on March 24 or 25.Photo:
Signs of Unstable Snow
Observations
Terrain: Parked just past the Canyon Creek bridge at 2200ft. Thin snow cover with bare patches on NF-31 until 2400ft. Rode to Church Lake/Bearpaw and then to the Excelsior warming hut.
Avalanche: Saw two recent natural slab avalanches that likely occurred on 3/24 or 3/25. The one listed above (D1.5) and a second on a north aspect at 5200ft above Canyon Lake (D2). Both were about 12-16in deep. Widespread wet loose activity occurred on 3/25 with rollerballs and pinwheels on most sun-exposed slopes and several D1 wet loose avalanches.
Snowpack: Variable surface conditions. Moist snow on all aspects below 3000ft. 2cm thick breakable melt-freeze crust on E-S-W aspects above 3500ft. N aspects held cold dry powder snow above 4000-4500ft, and had a breakable melt-freeze crust below. The 3/18-24 storm snow settled to 12-16in (4F-1F) and is well bonded to the 3/18 interface. The 2/24 interface was moist and did not present any concerns. In a test pit on a north aspect at 5200ft near Church Lake, compression tests produced resistant planar fractures on the 3/18 interface and extended column tests did not produce propagation (CTM ↓40cm RP x2, ECTN 16 ↓40cm).
Weather: Obscured skies with thick clouds and poor visibility. Brief periods of very light snow and rain before 10 am. Light southwest winds.
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