Reporting in to confirm as Trent forecast, “persistent weak layers can be triggered remotely, from a distance, or from below.”

Triggered a D2 avalanche from below today (3/15) at 12:45pm in the Icebox of upper Porter Fork, which failed on the February drought layer.

Crown was two feet deep, 350 feet wide, 60 degrees at the steepest point, averaging about 40 degrees the entire length. Avalanche started at 9400 feet running 500 vertical feet. Slope faces northeast.

Toured this slope yesterday and today. Put the skinner yesterday concerned the path could be released on ascent. Chose a route that was unlikely to be hit if the path did release. Today’s avalanche is a repeater that first went naturally during the December storm cycle.

Column yesterday failed during isolation on the February drought layer confirming its existence in this area.

Ascending from the trailhead at 6000 feet to the Icebox at 9000 feet noted today was dramatically warmer than yesterday and the snow at 9000 feet was moist and sticking to my skins. Noted small wet loose slides occurred today off the Porter Slabs above the Icebox during morning sun. Winds were gusting a bit nothing terribly forceful.

Icebox is a huge path with upper, middle and lower portions. Today’s avalanche was just the upper portion, which is a small basin with a rim on the edge and a hillock at the bottom. Left yesterday’s skinner thinking to lunch and de-skin on the hillock. Gaining the hillock during a bit of wind, I thought about Trent’s statement persistent weak layers can be triggered from below, stomped my skis to deglop the skins, felt I didn’t like where I was standing as the slope released. Ran from the hillock horizontally toward the edge of the path where the skinner was as the debris rushed down toward me stopping ten feet away. The hillock where I had been standing was covered in 2 feet of debris which continued downhill for about 50 linear feet.

Debris did not hit the skinner.

First photo is from where I stopped after running away from the avalanche.

Second photo is looking up the debris path from the skinner with the hillock lunch spot in the foreground, the crown in the middle and the Mill B ridgeline at the top. A 100 square foot piece of hangfire released harmlessly just after I took this photo.