I began dropping cornices in the 99 Steps Chute area. I dropped at least 7 chunks descending the ridgeline to the North. Cornices were sensitive and very hard/firm. They were in the size of a small car for the most part. After the 7th chunk I released a small mini-van size chunk about 250 to 300 feet down the ridgeline from the 99 Steps Chute; and it struck the slope and triggered the slide. It propagated back up to the 99 Steps Chute and also propagated down the ridge at lease another 400 feet. The largest crown face area appeared to be at least 6 feet and most likely closer to 7 feet. It was difficult to get a good close look at the triggering point. Graupel pooling and extreme wind loading appeared to play a large part in the slab development. The slide occurred 130 feet down off the ridge where a cliff/rock face rolls over for steepness. The slide went to the ground at the top of all the starting zones. The aspect at the trigger point was ENE. Upon descending the ridgeline to the North, when the bowl loses steepness before the pass, I entered the East side of the bowl and experienced collapsing and propagating on 23 degree slopes. The aspect in this area is ESE.

Weather during the day was a combination of intermittent snow, gusty winds and partially clearing skies. New snow during the day was 2 to 3 inches. Winds were out of the SSW. Transport was heavy at times of the stronger winds. Loading was occurring well down the slopes. Propagation previously mentioned on the 23 degree slopes also was shearing in facets directly above the ground and on these ESE aspects there was not a m/f crust 5 inches above the ground. Cracking occurred with minimal slope movement. The stress crack was 3 mm wide. No other signs of instability were observed. This kind of deep slab instability appears to be isolated to upper elevation wind loaded areas on NW, N, NE, E, and SE aspects. The pattern appears to indicate that slides are breaking well down off the ridgelines and below the normal steep starting zones.