Professional Observation

Observation Details

Signs of Unstable Snow

We skied in the lower reaches of the Mammoth Lakes Basin this morning as the snowfall intensity was really picking up. Snowfall rates of up to about 2″ an hour were observed and we saw a few inches of accumulation during our short visit to a relatively protected stretch of forest. Winds were strong out of the SW and visibility was at times challenging out in the open flats of Twin Lakes.

New snow amounts were less than ~1 foot when we set out. The soft snow was right side up and overlaid old temperature crusts and chunky tree bombs, and larger patches of soft, dry snow. Deeper drifts of wind blown snow up to ~2 feet deep were found in more exposed areas near the high point of our travels at around 9000′, still below treeline.

Overall we stuck to relatively dense tree cover with only small pieces of terrain that approach 35 degrees. It was easy to get the new snow running as small Loose Dry sluffs in steeper areas. We triggered 2 small storm slab pockets on convex pieces of terrain on our third lap and started to see more signs of storm slab instability.

Snow Stability