Observation: NWAC Forecaster

Advanced Information

Weather Summary

Snow showers for most of the morning with a few breaks. A few periods of convective heavier precip (often graupel) coincided with some gustier winds. Otherwise, the wind was generally calm. It was snain/borderline snowing at the car when I exited just after noon.

Avalanche Observation Comments:

Came across a few shallow skier-triggered slabs during my travels. I was able to trigger some softer snow on test slopes that technically failed as slabs but behaved more like loose. Every time I saw a skier step out onto a steeper slope, snow was moving downhill, running on the crust.

Snowpack Observations

I found that the HST has a variable bond to the 3/31 interface, mostly depending on elevation, but to an extent aspect as well. At lower elevations, there is a favorable bond since it was warmer down there at the start of the storm. On slopes that typically see direct sunshine, the crust is burlier and it appears the bond is poor. The middle ground is typically northerly aspects where a crust still exists, but it's more subtle. I found that the bond on these slopes varied between poor and moderate. Definitely not a favorable bond at mid-elevations. I did not observe the ATL today. Hand pits throughout the day helped highlight how the bond changed with aspect and elevation.

Digging a pit at 4800' on a northerly aspect, I found that the HST had multiple density breaks and interstorm layers that failed during tilt tests, shear tests, and small column tests. As alluded to above, the snow lacks a lot of cohesion but was failing in very soft slabs at these interfaces. There were pockets of graupel dispersed throughout the storm snow and on the surface.