Frenchman Creek

Sloppy conditions were the name of the game today! Light rain at the trailhead and a very moist upper couple of inches of the snowpack made for challenging travel conditions both on snowmobiles and skis. We travelled on W-SW-S-SE aspects to further investigate the instability of widespread persistent weak layers given relative lack of observed avalanche activity during recent storms on these aspects. We experienced a couple of collapses and found propagating unstable results in stability tests on buried weak layers.

Although it may be getting harder to trigger the persistent slab avalanches in areas with deeper snowpacks, like we visited today, the avalanches triggered would be quite large given the 2-3 feet thick slabs of snow sitting atop the weak layers.

Felt two collapses at 8250 feet on SW aspect that seemed to run ~50' in all directions. Observed a handful of small wet loose natural avalanches.

Overnight snow: 4-6" (10-15cm) of high-moisture-content snow fell with warming temperatures overnight and, sadly, some rain this morning. The thickest/stickiest/sloppiest wet-snow was below 8500 feet.

Post-Christmas snow: ~1.5 feet (50cm) of settled recent snowfall has accumulated above the old pre-holiday snowpack and has come in generally right-side-up.

Persistent weak layers: We found the 12/14 - 12/7 crust-facet-sandwich above 9000 feet. They were decomposing and nearly acting as one melt-freeze crust complex. Stability tests failed and propagated in weak sugary facets immediately below these crusts.

Quick Pit: 9200 feet W aspect - HS100cm - stability test results: 

• ECTN14@75cm on subtle density change
• ECTN24@65cm on preserved stellars
• ECTP29@29cm on facets below 12/7 crust
• PST 30/100 END @ 29 on facets below 12/7 crust