Avalanche Skier accidental west face of Serratus Mountain, Tantalus Range

Day 3 of Tantalus Traverse. Last push was from the Haberl Hut along the west side of Serratus to the col between Serratus and Ionia. Then continue down to Lake Lovely Water and out the Summer trail. Unfortunately we awoke to a full whiteout. We had to push on or be grounded for days. We traversed the west slope in zero visibility. Right before we made it to the buttress leading up to the col my partner was involved in an avalanche and taken over the cliffs below. He was carried about 120m down slope. He was partially baried and able to clear an air pocket. The avalanche was a size 2 isolated windslab on a unsupported slope, approximately at 2100m on West aspect. The crown varried between 20-40cm. Due to visibility the width is somewhat unknown but propagating potentially to 40-50m and running approximately 300m down slope. The bed surface was firm, potentially barried sun crust. Sunday brought some solar as well as E winds and cooling temperatures over night all contributed to the newly formed windslab. No new avalanche activity was witnessed during the traverse and multiple snow tests were performed with no concerning results. The avalanche was unfortunate yet quite isolated. The conditions this spring are very complex with so much spacial variability. It is full on winter in the mountains and every slope needs to be treated differently. Stay safe everyone.