Gunnison

All of the slab activity in the past week has been in wind-affected terrain. Seek out softer, wind-protected snow in sheltered terrain for better riding conditions and a minor chance of triggering a slab avalanche.  You'll have to manage for more predictable point-release avalanches on slopes that roll steeply to around 40°, and they might grow larger than expected as they entrain the weak snowpack.

As we get further from last week's wind-loading events, we're restructuring our avalanche problems.  We've merged our wind slab problem from last week into the persistent slab problem and expanded the rose (to include SE aspects NTL).  Last week's wind slabs formed over facets or faceted crusts and are not healing quickly. For example, our forecast team remotely triggered a windslab yesterday near the valley floor in the Slate, and similar action was reported from the Aspen side. You can still use surface clues to identify this newest generation of soft or hard slabs scattered across leeward and concave features from prolonged north-to-west winds.  In contrast, our older generation of persistent slabs - the "Holiday Slab" - is less conspicuous, larger, and less likely to be triggered.  We've added dry loose avalanches to the vacant spot in place of wind slabs.  This isn't a new problem, but one that has gradually developed during the past weeks of cold weather and likely won't improve with clear, dry weather on the horizon. Most facet sluffs are expected to be D1 to D1.5 in size, with some outliers up to D2 in the largest terrain features (like we observed yesterday targeting suspect bed surfaces on Schuylkill Ridge). Our video from the field illustrates all of these issues.  Yesterday's travel advice simplified into wind-sheltered vs. drifted terrain still applies, so I'll let it ride for another day here.

• Wind-sheltered terrain:  The Holiday slab is softer, thinner, and has decayed significantly, making for very low odds of triggering a slab avalanche.  You can use stability tests or feel the snowpack for a loss of cohesion to gain further confidence.  As you move into steeper terrain, the snowpack is typically even shallower, and on some slopes, you'll be able to trigger facet sluffs that start small and slow but pick up steam and mass in bigger terrain.  Use defensive or off-fall-line riding and good communication to manage that problem, or choose mellower slope angles.
• Wind-drifted terrain: Most commonly near and above treeline, but also on open below treeline slopes from recent down-valley winds (like last weekend's East Bowl slide or yesterday's remote on Schuylkill Ridge).  The most recent generation of drifted slabs is fairly easy to recognize and avoid: Look for stiff, smooth, rounded deposits in concave features or below ridges. Some of those slabs formed over persistent weak layers so they are taking longer than usual to heal.  The thicker persistent slab problem (the "Holiday Slab") is a lower likelihood threat, but it can be difficult to identify problematic slopes or terrain features. Slopes with recent or previous wind loading (as opposed to erosion) are most worrisome.  You can reduce your risk in those drifted areas by traveling where slopes are consistently deep and uniform. However, there's a degree of uncertainty in that strategy, as illustrated by this video. 

Check out our latest weekly summary for more insight into our snowpack structure and avalanche patterns.