Avalanche

Alpental - Denny Mountain in undisturbed terrain

Josh LipkowitzSnoqualmie Pass
View on map
Observation photo 1Observation photo 2Observation photo 3Observation photo 4Observation photo 5Observation photo 6Observation photo 7

Quick report

I took advantage of a window of visibility to try and assess the recent cycle and put a shovel in the snow to see where the water had percolated down to. I saw less avalanche activity in the surrounding terrain than I expected. A large glide avalanche was the most substantial slide I saw, in addition to some fairly gouging wet loose avalanches on Kendall. However, many of the aspects visible from the top of Alpental are W-S-E, and subsequent tours that get a better look at slopes on the northern half of the dial are needed to properly characterize the cycle with a bit more certainty. 

There was an overnight refreeze which left a thin, brittle, and slick surface crust at all elevations. I was hoping that the new snow would fall on a moist surface, but alas, it will fall on a frozen crust which could prove problematic for bonding with the incoming snow. Below the crust, the snowpack was very wet down about 2ft to the 2/13, where the water had pooled. To our surprise, the water in our snow hole had not made it below that point. While many observations from the lower elevations seem to point the much of the water having drained all the way through the snowpack, that certainly was not the case at our mid-upper elevation snow pit. The 1/10 complex was down about 3.5ft and the facets were the same as they have been, dry and weak, as evidenced by another low-cut length End result in a propagation saw test. With the slowly lowering temperatures, the snowpack is taking a while to refreeze and is keeping the 1/10 in the back of my mind until things lock up above it. 

Weather

Cloud Cover
overcast
Snow Avail For Transport
none

The cloud deck lifted off affording some good visibility. Winds increased through the morning into the moderate range. By 11 AM, the cloud deck lowered back down and light snow began to fall.

Snowpack

A thin and brittle surface crust capped wet snow down to the 2/13 interface, about 55 cm below the surface at 5300ft. The crust was ski but not boot-supportable. Snow below the crust was wet. At the 2/13, the water was pooled and the layer was slushy. Below that point, the snow was dry. The 1/10 complex was down about 110 cm and remained unchanged. Weak 1-2 mm facets below a zipper crust at the top of the interface. 

PST 42/110 End at the 1/10 in the facets. 

Avalanche

Size
D2
Type
WS
Count
2
Aspect
NE
Trigger
N
Elevation
5000 ft

From my vantage point, I could mostly see W-E-S facing terrain. I also observed a small wet slab on Rampart Ridge and numerous additional open glide cracks and a few wet slabs on a driving tour on 2/23.