Quick report
- Cracking
- widespread
- Collapsing
- specific
Down valley winds had worked through the terrain here at all elevations, redistributing and thickening slabs into crossloaded drifts 6" to 20" thick, typically F+ or 4F, with pockets of hard slab as well. Some of the most unique remote triggering conditions I've experienced: remote triggers were occurring from long distances (up to 1000 ft!), crossing terrain features that seemingly lacked a slab, just a connected crust. It was hard to find wind-protected terrain out here, but the new snow was still slabby in the most protected areas. We traversed across the top of a few sheltered NE-facing start zones BTL without anything notable, but observed a couple of avalanches (likely remotely triggered?) on similar types of terrain one gulley away. Wind-drifted slopes were reactive at all elevations on facets or faceted crusts, often producing loud audible collapses or shooting cracks.
We saw shooting cracks on many slopes and also observed numerous collapses (some localized, some rumbling), most commonly on wind-drifted terrain features. We also triggered numerous avalanches, many remotely/sympathetically. These were all on our early January facets or faceted crusts. The only aspect that I couldn't produce signs of instability on was due south, or on wind eroded slopes.Weather
- Cloud Cover
- overcast
- Wind Loading
- moderate
- Rain Elevation
- Nope
- Recent Snowfall
- 15 to 25
- Snow Avail For Transport
- moderate amounts
Observed ongoing windloading in the alpine, though winds were mellowing out compared to last night's drifting. Light snowfall with less than a few cm's during our travels. Snowfall rates ramped up around sunset.
Snowpack
Found sounds of instability on our January PWL on SW, W, NE, E, SE aspects near or below treeline. Didn't travel on N or NW. Nothing notable on S BTL.
Avalanche
- Size
- D1 R1
- Type
- SS
- Count
- 11
- Aspect
- SE
- Trigger
- AS
- Elevation
- 10000 ft
In the Upper Slate, there were several natural avalanches, both on windloaded slopes ATL (up to D2), and a few small slabs (D1) in relatively sheltered terrain BTL. We remotely triggered numerous small slab avalanches as well; most were cross-drifted slabs on exposed below treeline slopes, a few were in relatively protected terrain. All of these avalanches appeared to break on our early January PWL: facets or faceted crusts. Decent visibility of below treeline terrain, and the only activity observed down-valley from Pittsburg was a narrow soft slab in Happy Chutes. Limited vis of alpine terrain.