Northern San Juan
AvalancheColin Mitchell · Jan 22, 2021 · Southern San Juan
Weather
Overcast skies with some low clouds drifting around the peaks. Winds were calm at pass level with a few stray snow flurries.
Snowpack
The snowpack in paths with a southerly tilt, like East Lime, the Waterfall/Springs area, Henry Brown and the Engineers have melted back to bare ground or to thin patches of refrozen melt/freeze grains from a few inches to up to a foot deep. The snow on the ground is largely irrelevant in these locations, and any avalanche activity would be limited to storm snow instabilities. West Lime has been battered by winds and sun over the 25 days which have passed since our last significant storm. Old bed surfaces from mitigation on 12/29 are still visible with this weeks meager snowfall on top. The recent snow layer is 2-6" deep and is F-hard mixed forms with rounds dominating. Any avalanche activity from this storm will break at the interface with the old bed surface, on one of the older wind-hardened surfaces, or higher in the storm snow. Overall, thresholds for avalanches that would threaten motorists or require mitigation are quite high for this highway section Minimum 16" for mitigation at any of these paths, and if spread over several days, more like 24". The Champion group remains thin, completely unconsolidated facets with possibly some wind or sun crusts at the surface in exposed areas. The crown form the 12/28 avalanche in lower champion is still visible, along with terrain roughness like rocks, shrubs and logs in the start zone and short track. Road hits from this storm are quite unlikely from the larger paths in this group, but due to poor structure and the potential for high consequence avalanches, a mission here with the 105 would likely be a go with 18" storm totals.
Avalanche
No new or recent avalanches observed