Mammoth Lakes Basin

Mostly cloudy, warm, no winds, t-shirt weather for uphill travel even above 10,000'.

Upper snowpack thawing up to 10500'.

Lower snowpack still not wet above 9000'.

Below treeline: Total snow is between 2 and 3 feet. Ski penetration to the ankle. The top few inches of the snowpack were wet on East and West aspects in the trees and clearings. Surface snow was moist on North aspects. Liquid water was dripping from trees onto the snow surface all day. A few roller balls in steep SE terrain at 8500'. Liberal skin wax application is required for trail breaking. A quick hand pit revealed that weak layers at the base of the snowpack under previous melt-freeze crusts were still moist to dry.

Near treeline: Total snow is between 2 and 3 feet. Ski penetration varies by aspect. Greatest in soft snow in steep north-facing terain - it was about 25cm. Skis stayed at the surface in wind-affected snow at ridges and previously wind-loaded East aspects. The top few inches of the snowpack were wet to moist on East and West aspects in the trees and clearings. Surface snow was moist on North aspects. By 4 pm thin melt-freeze crusts (zipper crusts)  were developing at the snow surface on previously sun-exposed slopes.

Above treeline: Visual observations only. North and east start zones are wind-pillowed from 1/24/24 snow and SW wind. A few D2.5 natural avalanche crowns are visible from the same storm. These likely failed on PWL's at the ground.

I dug a pit on a north aspect at 10,600' below a short cliff band where HS was 120cm and the slope angle was 35 degrees. The layer of concern was F hard, 6mm, dry, Depth Hoar, 95cm below the surface under a strong (1F and P) mid-pack slab. The layer propagated in the extended column test (ECTP22). See the attached profile for details.