Northern San Juan

Avalanche

Susan Hale · Jan 29, 2016 · Southern San Juan

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Weather

Clear, calm, warm until early afternoon... Winds picked up mid-day.

Snowpack

In W. Lime Creek path: Highly variable snowpack. Mainly due to it's somewhat protected E aspect at this time of year -- always interesting how dramatically each undulation in terrain affects the snowpack exposure to winds and sun. Depths in short distances ranged from 18" to a meter deep. Sections that avalanched during the Christmas storm were very shallow and completely faceted (they will be early repeat offenders). On the flanks of one of those shallow "bed-surface" areas we got a 15-20 ft shooting crack on a very soft faceted slab (4F- hardness! Basically the facets below were weaker than the weak facets above. Nearby, cross loaded sections (also more sun affected) were much deeper and dramatically stronger, with 1F slabs as much as 50cm thick. Here, the surface is our initial problem with the incoming storm - with a 1-2cm fragile mf crust and assoc facets.

Avalanche

Future: Early on in a loading event (12-15 inches snow with some wind) we may see pocketed slide activity (mitigated or natural) out of those areas that had previous avalanche activity and are now shallow/weak. Several of these could affect the highway.