Northern San Juan
AvalancheColin Mitchell · Dec 27, 2021 · Southern San Juan
Weather
Southwest winds continue to rake the San Juan, mixing down to 9,000' or lower. Intense wind-loading near and below treeline was forming drifts and cornices almost anywhere you could imagine, guardrails, plow windrows, trees, rocks, vehicles, etc. Skies were overcast to obscured with light snow at pass level and temperatures in the mid-teens.
Snowpack
Mitigation on the 24th reduced the volume in highway paths on Coal Bank pass, but snow and wind over the last 2 days have begun to reload them. Overall, volume was still noticeably reduced, but crowns had been blown back in, and were hard to discern. In paths with a southerly tilt, like Henry Brown and the Engineers, last week's triggered slides ran on a stout melt/freeze crust. Cold temperatures over the past few days inhibited bonding of the new snow to this crust, and hand shear tests released with easy pressure. At West Lime, explosive triggered avalanches released on a thick layer of faceted snow at the base of the snowpack. Today's snowpack tests produced moderate results, ECTP 17 and 21 on what was left of this layer. Winds have quickly packed and settled the new snow. Hardness was 4f-1f+ in any exposed location.
Avalanche
No new activity observed today