Observation Date
2/2/2021
Observer Name
Zimmerman-Wall / Grainger
Region
Salt Lake » Little Cottonwood Canyon » Red Pine
Location Name or Route
Red Pine
Comments
Goals of the day: 1. Target uncertainty with regards to what slide paths ran during the last cycle (1/30/21) and what has yet to release in the alpine terrain of Red Pine/Maybird. 2. Map surface conditions ahead of the next loading event. We were pleasantly surprised to see that upper Red Pine went through an extensive natural cycle. The entirety of the upper north through east facing portion of the drainage (Lake Shot et al) had run and debris reached almost as far as the Lower Red Pine Lake. The effects of the wind event from 1/27-1/28 and the subsequent snowfall (40cm) allowed for the larger slopes to be connected for the first time during the season. It was truly amazing to see crowns that wrapped around terrain features and aspects. Even down in the rolling terrain above the lake we were able to see evidence of significant avalanches in unusual places. Would be difficult to call any of these greater than D2.5 due to the nature of the slab. Although the Lake Shot path has significant relief, the crowns were only around 90cm-1.25 m deep and the flanks quickly tapered to 50-60 cm. Although it took out the majority of the snow cover from the season, there just wasn't that much volume in the deposition zones at the toe.
Small test slopes at mid elevation on the way to Maybird provided solid evidence that the snowpack was still adjusting and we triggered one small avalanche by kicking a cornice feature on a steep rollover.
While it was clear the majority of the hazard had relived itself in the alpine, would expect many of these paths to reload and possibly repeat. There is still weak snow left in the bed surfaces. And the mid elevation slopes that did not run may still be suspect. Although our snow pit showed that the mid pack has become quite stout above the 20201211 layer, the facets will need more time to undergo the effects of pressure and sintering. But maybe in certain places we are putting the right dynamics in place to gain strength. Until then, the avalanches are going to be large and un-survivable if triggered.
Photos:
Upper Drainage crowns



Photos
Lower Lake slide and test slope after cornice kick.



Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates