Nadahini upper treeline

<p>Initial observation of conditions put the Avalanche risk at low due to no critical warming, only 1 to 2 inch of recent snow, no signs of cracks or slab avalanches, no wind loading. So I embarked up the E face of nadahini in 30-35 degree slopes ("challenging" or blue terrain per ATES map), starting from the green shack. Weather was some very light snow, totally overcast with flat light, and no wind. Once I reached top of treeline I noticed a shooting crack that went deeper than the 1-2 inches of new snow and under the medium density crust that had formed from the warming last week. It was several meters long. Soon after that I triggered a class 1, 1+ slab just above a bowl I just finished traversing. The release was very loud. Crown was just under a convex roll which flowed into the small bowl. The slab moved only 10m or so and stopped, but the crown was over 1 foot deep (I did not get closer for a better measurement. See the picture). This made me reassess the dangerator and avaluator and immediately ski back down and stick to <30 degree slopes the rest of the day. Especially since the slab was deep and probably indicating a very weak layer buried @ 30+ cm & possible persistent slab problem. And this terrain is very undulating so lots of convex rolls and some flat spots (terrain traps). Additionally, due to the near white-out I could not see anything above me especially in the Alpine so could not assess start zones above me. However, the ski down was magnificent with great terrain and great powder conditions with a medium density crust a few inches below the surface.</p>

Terrain Ridden

Alpine slopes, Convex slopes, Steep slopes, Open trees.

Avalanche Conditions

Slab avalanches today or yesterday.

Whumpfing or drum-like sounds or shooting cracks.

Snow Conditions

Crusty, Powder.

Weather Conditions

Foggy, Cloudy.