Observation: NWAC Forecaster

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Weather Summary

35cm from the storm on 12/18. Inversion with valley fog below around 4,500ft, very mild above that with intermittent sunshine poking through, then becoming overcast later. Light drizzle towards the end of the day, which was freezing rain below the inversion.

Avalanche Observation Comments:

We observed a couple of recent storm slabs that were about 35-40cm deep, and in the D1-2 range in size. They likely ran on 12/18 with the storm. These were in open, steep and convex slopes between 4,500ft and 5,600ft and on NE-SE aspects.

Snowpack Observations

Snow surfaces became moist above the inversion by late morning. Rollerballs occurred on steep slopes in many places, but we didn't observe any actually wet loose avalanches. It did seem possible to trigger one in the right place though -very steep, sunny slopes.

We dug a quick profile on an E aspect at 5,440ft to check the structure and for weak layers.
We got moderate resistant planer Compression Test results on a layer of preserved but now decomposing stellars down 35cm (likely the storm interface from 12/18).
An Extended Column Test failed but didn't propagate on this layer.
I was able to identify the same layer as the culprit for a recent slide at a crown lower down on the slope.

No results with Deep Tap Tests on ever so slightly weaker snow (P vs P+ above) above the 12/8 freezing rain crust, down 100cm.

The snowpack felt like it has gained noticeable strength and settled with the warmer temperatures.