Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Key Points

• With cloudy conditions and minimal warming today, we headed for tree’d terrain in the southern part of the forecast zone. Toured to terrain above North Lake in the NF Bishop Creek drainage under very calm conditions and partly to mostly cloudy skies. It was mild with a temperature of 29degF at 1100am @ 10000ft.
• Ski penetration averaged around 5-15cm on shady, non-sun affected surfaces above 9000ft, with boot penetration averaging from 25-40cm in some places. Overall, the snow was faceted throughout the snowpack on shady aspects and was very loose and unconsolidated where shallow or where it was lying on boulder fields or other very rocky terrain.
• Average snowpack depths averaged 1-2feet in depth in the flats and sunny aspects with upwards of 4 feet on northerly sheltered terrain above 10000ft. Westerly and southerly aspects are primarily rock and looked severely wind affected.
• Soft turns were to be had on near surface faceted snow above 9000ft in sheltered northerly terrain and even some windboard on lower easterly terrain has started to facet a bit and make for a little less harsh surface to travel down.
• Dug a snow pit at 10,200ft and found 95cm of total snow. There was 15cm of surface faceted snow– Fist in Hardness overlying a faceted, but still robust mid-pack (70cm mid-section) that was right side up going from 4Finger hardness down to 1Finger hardness. The bottom 10-15cm of basal snow had well developed striated faceted snow that was upwards of 3mm in size. I wouldn’t quite categorize it as depth hoar, but its close, it was bordering on Fist hardness. Block tests in the form of Column Tests and Extended Column tests produced NO results, even on the weaker basal snow.