Northern San Juan

Avalanche

Ben Pritchett and Jason Konigsberg · Mar 14, 2020 · Northern San Juan

Weather

Skies were mostly clear for most of the day. Late afternoon saw a brief increase in cloud cover, clearing again towards evening. Although we did not observe much wind below treeline, it sounded like some strong gusts up high. No significant snow transport observed. I measured 5 inches of new snow at 9600 feet near the old townsite of Sherman.

Snowpack

A very weak snowpack overall. A couple inches of new snow on a crust up to 11,000'. Below the crust is a mess of Fist to 4-Finger hard depth hoar. Generally unsupportive on skis. No slab for a current Persistent Slab avalanche problem at the elevations observed, but a little drifting on this snowpack, or a future slab-building snowfall event would make for a dangerous structure. Add enough water to melt the crust and you an instant Wet avalanche threat that would most likely gouge to ground (like recent full-depth wet avalanches below 9,000' around other parts of the Gunnison Basin).---On an east aspect at 11,300 feet we found a snowpack with melt water saturating previously dry depth hoar. Repeatable propagating results in an ECT at 45 cm down from the surface (HS = 70 cm). Although this structure screamed Wet Slab avalanches, we did not see much evidence of avalanche activity.

Avalanche

A couple triggered tiny Loose Dry avalanches. Overall, we observed a lot of terrain around CR-30 and only one large avalanche was noted.