Vail & Summit County
AvalancheBrian Carisch · Feb 5, 2020 · Vail & Summit County
Weather
Sun and clouds, warm, and no wind.
Snowpack
At treeline and above treeline, we were skiing a W facing slope of the northern Gore Range. 6 inches had fallen 2 days earlier. Avy forecast for the day before was 2 at all elevations, and most unstable Easterly from N to SE. There was quite a bit of wind loading on isolated spots near the N to NW ridge. We dug a hasty pit to 2 meters in depth at 12,000 feet, and didn't find any clues or any clear slab indications. We were at our transition point, still on somewhat of a wind affected snow, and spoke about the fact that this didn't mean there was no persistent slab present, just that it wasn't present right here.
Avalanche
Skier 1, 2 and 3 made 2 descents of 12380 from around 12,000 feet or appr. 350 feet from the summit. We started on the N side of the W slope where we measured a slope angle of 27 degrees. Skiing one at a time after 300-400 feet, we stopped where the slope pitched over to have eyes on each other as we skied the last problematic pitch down to the bowl. Some crusty wind affected snow, led us to very soft, fun powder. Everyone agreed it was good, but didn't love the last pitch where it was likely just over 30 to 35 degrees. Our second decent took us a little further S into the face. Here we found rather large wind slab had formed to make a small head wall above a nice gully down to the basin. Skier 1 and 2 skied this line in leap frog fashion, with an amazing run, that was under 30 degrees the entire run. Skier 3 took a line near the first run down, and skied out. Skier 1 and 2 went back to the hut for lunch, and to talk to other partners there about going back out in the afternoon. Skier 3 left the hut. Skier 1, 2 were joined by 4 and 5 to go back, and find more turns like the second run they had experienced. We all went to the same top out as the first runs, but decided to go even further S, on what looked like the same type of skiing we had in the morning. 4 and 5 went first, going down that same gully which 1 and 2 had skied early. 1 and 2 both went to the next two gullies skiing them without indecent, but both coming away with a feeling that it was steeper than the gully. We had now skied a total of 10 lines on this face, and as the sun was getting low skier 1 and 2 decided to take it to the summit, and come back down to ski the S most line on the face which appeared to be less steep than their previous run. 4 and 5 would only go back to the same high point as before and decide on a line themselves. After the summit and taking photos, 1 and 2 skied half way down on very low angle, decent snow to about the half way point. Looking down now, we saw a slide path almost directly below us. It was a frantic few moments when we distinctly saw a single skier in the middle of the pile. We couldn't see if they were partially buried, or digging for the other skier. After a bit of yelling and we realized skier 5 was standing on a small rise near some trees. Both skiers were accounted for, but now we needed to get down. We chose to go even further skiers left (S) and try to come back to the slope from that angle, but this proved to be a poor choice. it was now clearly much steeper, and we were going to need to get into the slide path, and ski down the old snow. We re-grouped at the toe of the path, discussed what happened, and made plans to get back to the hut, as the sun was setting. The slide was triggered by skier 5 skiing directly after skier 4 on almost exactly the same line, between rocks and trees on a slope of 35-40 degrees, at treeline, at 5:00 pm just a few moments before sunset. It is likely 35+ degrees for only 50-100 vertical feet, and it quickly drops down to less than 20 degrees. He was carried by the snow down 200-300 feet, ending buried up to mid waist in snow that wasn't too hard, as he was able to dig himself out. It was a large fracture line of 3 to 3.5 feet running between the rocks and the trees approximately 100 feet wide. It is my guess that the slide was TL, W, SS, AS /u, R2, D1 A long day with many good decisions led to being complacent and sloppy at the end of the day. It was warmer later in the day, we were skiing on steeper slopes than we had intended, and our guard was down.