Natural avalanche on southeast side of Arden

Two skiers came across a natural avalanche while touring on the southeast side of Arden peak seen from Maid of the Mist basin. The avalanche appeared to be around 100 feet wide at the crown and ran all the way down the bowl until things flattened out -- maybe 700 feet. The avalanche appeared to be maybe a foot deep at the crown, appeared to have broken on a wind slab on the fresh snow. We dug a hasty pit that showed weakness on that same layer of new snow around 10-12 inches deep at the interface with the previous layer. We were planning to ski the Pinner on the north east side Arden peak, but upon seeing evidence of instability we scaled back our objective and skied Maiden bowl.