Triggered Avalanche 2/6/2023
Wind Slabs & Tracking the Dec Weak Layer
Avalanche Pass Area
Triggered Avalanche
Dry/Loose (Sluff)
D1: Relatively harmless to people.
Small amount of sluff running as anticipated on a short ~40 degree slope on a W aspect @~3300'
Observation Details
Overcast skies. Temperature near freezing point and falling throughout the day. Intermittent light sleet and snow falling for brief periods of time. Pit dug on NE aspect at 4325' revealed 145cm total with a stiff wind slab 15cm thick. CT test results; CT2 Q3 @110cm. CT11 Q2 @70cm (December rain crust). ECTN8 @70cm, continued with test and achieved full propagation on 11 at the same weak layer @70cm. PST 45/100 end @70cm.
Seems as though there is still some chance of a fracture propagating on the December rain crust given the right set of circumstances. Our primary concern was releasing a smaller wind slab and having that step down due to the aforementioned PWL @70cm. Pronounced spatial variability is proving challenging to make accurate predictions of the snowpack in any given location. Testing for the potential for fracture propagation @ the December rain crust continues to provide mixed results given location, elevation, and aspect. Even multiple tests within the same pit yielding contrasting results.
While skiing a W aspect we were able to get a substantial amount of sluff to run on steeper slopes at moderate elevations (~3300 ft).