Northern San Juan
AvalancheAngela Hawse · Dec 13, 2015 · Northern San Juan
Weather
Significant wind transport of new snow in the alpine from the NNE until 1:00 pm, decreasing throughout the afternoon. Winds were light at TL with a few errant gusts. Clear skies with temperatures ranging from 15 - 25º with southern aspects feeling significantly warmer. A few high clouds moved in from the SW by 2:00 with increasing coverage by 4:00.
Snowpack
HS was variable from 20cm on southerly tilts to 200cm on sheltered, lee slopes on north aspects to TL. Average HS was 70-100cm. Yesterday's storm snow ranged from 10cm on southern tilts to 30cm on shady aspects . Northern aspects in the alpine were scoured with considerable sastrugi and fat, cross loaded pillows. Southerly aspects were less wind affected with a blanket of fresh snow to ridge tops. We found the persistent slab from the Nov. 17 storm to vary in thickness on northerly aspects at TL with little tension and 4-1F hardness. The foundation of basal facets was weak where observed and suspect. We found good quality skiing with a supportable base at the interface with the Dec 4 snow, and some wind skin to 3cm on more open features. The only reactivity we could get on this layer was on very steep unsupported, mini terrain features with ski cuts and hand shears.
Avalanche
A few very shallow crowns were observed on northerly aspects in the alpine that likely ran during the storm. Quite a few bold lines were skied today with no consequence.