Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Key Points

I toured up from mill city to the top of the Sherwin ridge above Mammoth rock today. After reaching the ridge i traversed to the Perch and dropped in on an easterly aspect before traversing to the main avy path.

Snow below treeline was quite moist and sticky by 9 am when I left mill city. the now pack in the Sherwins is still quite transitional and some minor glopping was experienced along my ascent. Surface snow was pretty uniformly moist which helped limit the glop factor. I found some cold surface snow above 10,000′ near the ridgeline in shaded areas but even areas with intermittent or diffuse sun exposure were moist. 2-5 cm of moist snow on the surface depending on the elevation and solar input. In several areas the moist snow is resting on old melt-freeze crusts however in shaded true northerly terrain I also noted areas with a few cm of cold new snow or even some old faceted snow below the moist grains.

Ski penetration in undisturbed areas along my ascent was about 25 cm and boot penetration was over boot top.

Rollerballs were very easy to initiate along the skin track with pinwheels growing to 2′ in diameter pretty easily.

While walking the ridgeline to the perch I observed a small natural Loose Wet avalanche that occurred in the Hammil Bowl area of the Mammoth Lakes Basin. I can’t confirm this happened today but it looked to have occurred in the last 48 hrs.

Dropping the east aspect off the perch I found old surface snow to be quite moist even in the shade. I was able to initiate one very small loose slough of wet snow that ran about 40′ but nothing of concerning size.

Rollerballs and Pinwheels were nearly impossible not to initiate along my descent to the golf course and the skiing was a bit harrowing.