Detailed Observation

Date2020-04-18
LocationHaines
ObserverJeff Moskowitz
AvalancheN

General Observations

A few examples of the wet loose daytime avalanche cycle that happened this past week. These were natural avalanches on all aspects at all elevations caused by solar radiation and above freezing temperatures. Did not observe any slides that stepped down to old dormant layers. With above freezing nighttime temperatures and rain on snow it will become a possibility. The sun is heating up underlying terrain such as rocks, cliffs and trees. Rockfall occurred at all hours of the day due to expansion and contraction process from the freeze thaw. Open slopes at upper elevations had a solid overnight freeze with about 10cm of crust. Below that a slighty up-side down 20cm of 3/8 deposits on top of the old snow interface. The forest held isothermal snow as did lower elevations.

Remember: An overnight clear sky does a better job to keep the snow surface colder, than an overnight cloud covered sky which traps heat and may not produce as solid a freeze.

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Weather Observations

Observed Avalanche Activity