Professional Observation
Basic Information
Observation Details
Observation Date:
April 21, 2023Submitted:
April 23, 2023Observer:
PAC - Kevin StudleyZone or Region:
Lick Creek AreaLocation:
Hum LakeSigns of Unstable Snow
Recent Avalanches?
YesCracking?
None ExperiencedCollapsing?
None ExperiencedSnow Stability
Stability Rating:
GoodConfidence in Rating:
ModerateStability Trend:
SteadyBottom Line
Weak, facets sitting atop a MF crust on north aspects presented poor structure. We did not receive propagation in our test pit, but poor structure overrules propagation. Persistent weak layers are abnormal for this time of year. Solar aspects had a layer of wet, mushy snow buried beneath a MF crust. The snowpack is still in transition from a dry, winter snowpack to a spring, isothermal snowpack. We are not very far along in this transition yet.
Media
Advanced Information
Weather Summary
Cloud Cover:
Mostly CloudyTemperature:
Not observedWind:
Moderate , SWScattered snow showers throughout the day. Intermittent squalls of graupel. Limited solar radiation, but enough to heat things up in a short amount of time. Moderate SW winds at ridgetops were transporting snow on NE slopes.
Snowpack Observations
We dug two pits. One on a E/SE aspect and one on a N/NE. Two very different snowpacks depending on aspect.
The solar aspect had several knife-hard MF crusts. A few inches of new snow sitting atop recent MF crust was becoming moist by mid-day Friday. The layer of concern was about 8" of wet, mushy snow sitting below an older MF crust. This crust was several inches thick and insulated the wet snow from cold temperatures. Moist snow observed for at least 3 feet down.
The north pit had over a foot of recent, wind-deposited snow sitting atop a layer of small-grained facets, just above a MF crust. This layer of facets is the layer of concern on north aspects. No propagation noted in this pit, but the poor structure is alarming, especially for late April.
