Humphreys Saddle to Allison Clay
Quick report
- Cracking
- isolated
We travelled up to the Humphreys Trail saddle, noting limited amounts of cracking and instability. However, instability slightly increased above 11,000 feet. At the Humphreys Trail Saddle, while on belay, we ski-cut a small test slope with a significant rollover (~40 degrees). Results were minimal, with shooting cracks ~5-10 feet. However, in our minds this was not unexpected as this slope was ~40 degrees and had a significant amount of recent wind loading. Minimal reactivity beyond cracks was noted. We then traveled across Rustler, noting some isolated and stubborn reactivity in wind-loaded zones (i.e., behind trees, etc.). Moving across the Temptations, we saw no signs of instability, with mixed snow conditions (wind buffed, new snow ~10"). On the Allison Clay Ridge, we noted significant wind loading off of the ridge up high and decided to take a more conservative route down, skirting the edge of the wind-loaded ridge and having the first skier initiate a significant ski cut on the slope. However, the first skier triggered a large avalanche on an initial ski cut, propagating 500-600' above the skier and across the bowl (see avalanche observation).
Weather
- Cloud Cover
- overcast
- Wind Loading
- moderate
- Rain Elevation
- NA
- Recent Snowfall
- 28
- Snow Avail For Transport
- large amounts
Significant predominant southwest winds are likely in the 30-45 MPH range. However, winds were often terrain-specific, and direction was variable.
Avalanche
- Size
- D2.5 R3
- Type
- SS
- Aspect
- NW
- Trigger
- AS
- Elevation
- 11600 ft
We triggered a large wind slab avalanche in Allison Clay. We assessed the terrain at ~11,800-12,000' and noticed significant loading on the northwest aspect off of the southern ridge; we decided to enter on the far left of the path at approximately 11,600' in a less steep zone that was less loaded and safer, with easier egress options. The first skier conducted a ski cut at the top of the slope; a shooting crack ran about 10-25 feet to the left; the skier immediately proceeded to their predefined safe spot outside the avalanche path. The avalanche propagated 500-600 feet above the trigger location, running across Allison Clay Bowl, with an approximate 2-4(+) foot crown. The toe was at approximately 11,200', and the debris pile was 2-6 feet deep.