Took the sleds to Tunnel Creek to look at a NW facing chute off of Tunnel Ridge. The top of the cute was suprisingly wind scoured down to the 2/1 crust with only 1-2" fresh snow on top. On the other side of the ridge, we found 12-18" of new snow on top of the 2/1 crust. I rapelled down into the starting zone of the chute and dug a pit at 6,300'. The snowpack was only 120cm deep, and the pit revealed no results (ECTX), despite some faceted snow at the base. The top crusts were decently bonded and providing quite a bit of bridging strength to the snowpack below. We decided to ski the chute one at a time, communicate with radios, and reconvene at a zone of safety 1/4 of the way down. The shape of the chute is planar, concave, and not too steep with a ~30-33 degree angle. The side walls however, are steep much like a half pipe. It skied well at times but frozen roller balls hiding under the surface made for tricky navigation. Partners skied the left side of the chute finding these land mines, so I skied the right side and found better snow. On a left turn, I heard my friend yell "Avalanche!". As I looked right, I saw the crown propogating away from me. I skied away into a safer zone, and when I looked back across, the crown was 200' in length and 10-15" deep. The slide broke on the steep side wall, and because the angle of the chute was only 30 degrees, it did not travel any farther. It was only D1-1.5 in size and would not have buried anyone. While surveying the scene, another natural D1 dry slough came down the opposite side.
We quickly decided to exit the chute and seek a safe zone to reconvene.
While debriefing in very thick timber about 200 feet above Tunnel Creek, we heard a VERY large avalanche crashing down from sub Liebig or Grant. It was so loud and seemed so close, I anticipated getting some wind and powder through the trees. The noise lasted about 15-30 seconds, stopped for a minute, and then another one ripped for 10-20 seconds. Seeing these signs, we decided to call it a day. On the ride out, we could see a small crown up towards Grant and possibly a VERY large crown up towards Liebig. Visibility was bad, so it could have just been a cornice. Based on the roar, I estimate it was a similar sized slide to the one reported last Sunday in the same drainage.
The snowpack seemed at a tipping point with heavy snow in mid-morning. The 2/1 crust was not bonding well in places, and there were too many dry naturals to count. The sleds were covered with 5" of new snow in only 4 hours time, and it was dumping throughout the morning.
