Quick report
- Collapsing
- widespread
We took a quick afternoon tour up Doris Creek toward Blaine Mountain to take a quick peek at snow conditions and recent avalanches. It was an eventful few hours.
- A very large natural avalanche took out the northeast face of Blaine, failing 3'+ deep, propagating well over 1,000' wide, and wrapping around multiple terrain features. It ran full path, with some debris continuing across the bench and over the next pitch above the lake, where it triggered another 2-3' deep avalanche that ran down to the lake.
- There were also additional releases in adjacent terrain.
- As soon as we got into open terrain at 6,500', we triggered no fewer than a dozen whumpfs, many of which propagated widely and rumbled.
- Ski penetration was about 4–6", down to a ski-supportable density break in the storm snow. There was about 12–16" of recent snow.
- We observed minimal signs of instability within the new storm snow.
- Not that we needed more evidence of instability on the persistent weak layer, but large column tests produced unstable results (ECTP12, PST 33/100 END) down 55 cm on the buried surface hoar over a crust (January Drought Layer).
- In a sign of how bad this layer is around the forecast area, upon seeing 10-15 mm surface hoar in the pit wall, Rob remarked, "not as big as I've seen it elsewhere". Things are bad when 10-15 mm surface hoar feels comparitively small.
- This layer remains highly reactive.
- Snow conditions were excellent for snowmobiling and skiing in sheltered low-angle terrain, fully disconnected from any overhead hazard.
More media to follow on Friday AM.
We presume the main avalanches on Blaine occurred during peak loading on 2/17, though we also observed some filled in crowns elsewhere on the face that may have failed 2/14-2/15. Many widely propagating whumpfs.Weather
- Cloud Cover
- broken
- Wind Loading
- unknown
- Recent Snowfall
- 30
- Snow Avail For Transport
- large amounts
A cool day with light winds up until our high point on a bench at 6500'. Occasional sun pops in the afternoon.
Snowpack
Snowpit on an east aspect @ 6500' in an open clearing.
ECTP12 down 55 cm on 10-15 mm surface hoar (January Drought Layer)
PST 33/100 END same layer
Upper slab is mainly 4F, while the bottom half of the slab is 1F. A few decomposing thin and fragile crust layers in the 10 cm above the BSH layer.
Avalanche
- Size
- D2 R3
- Type
- HS
- Count
- 3
- Aspect
- NE
- Trigger
- N
- Elevation
- 6660 ft
A very large avalanche on the northeast face of Blaine, with additional releases in adjacent terrain and a widely propagating crown below the bench in the lower track triggered by debris. More debris on the one other alpine face we could see (though from an oblique angle in poor light).