Southern San Juan

Avalanche

Zach Taylor · May 12, 2014 · Southern San Juan

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Weather

Mostly cloudy for this time period, with very brief periods of sunshine on 5/9, 5/10, & 5/12 (no sun on 5/11). Breezy to very windy for most of this time period. Variable new snow fell in the drainage. I would estimate between 6" and 12" new but with the amount of wind judging exact snowfall was a challenge. Ridge top winds came out of the southwest with valley winds running directly west at 11,000'. Temps probably never got above freezing for the four days we were up there. The wind chill definitely did not.

Snowpack

Interesting mix of snow conditions. Still a lot of decomposing snow present on 5/9 and 5/10 above 11,000' mixed with sections of frozen melt freeze crust. Lots of new snowfall and wind drifting on 5/11. New drifts present this morning on primarily the east side of the compass but with many sections of the snow surface above treeline scoured to the pre-storm melt-freeze/dust layer crust while other sections were drifted 12"-18" deep. New snow seemed to be bonding moderately well with no cracking or collapsing or natural/human triggered activity noted in the area today (5/12) after the storm moved through the area. The north face of Mt. Wilson was comprised of a surface dust layer in places. In other places it was covered in newish decomposing snow and windslabs on 5/10 but this was noted before the storm came through and we did not go up high besides crossing the Rock of Ages saddle after the last two days' storm cycle.

Avalanche

While skiing the north face of Mt. Wilson from Navajo Basin I triggered one wind slab with a slope cut and another partner triggered another wind slab with a ski cut. Both were expected releases and no one was caught in the slides (both D1/R1 but big enough to carry one over cliffs on 5/10). The weak layer culprit appeared to be the most superficial dust layer in the basin recently. Lots of new snow since then. I would probably give anything in the area a day or two of sunshine and warm weather before venturing into couloirs in the area.