|Location:||Back side of Microdot|
Route & General Observations
Human triggered avalanche, partial burial. Multiple riders on slope prior to triggering avalanche.
|Trigger||Skier||Avalanche Type||Hard Slab||Aspect||North|
|Elevation||4500ft||Slope Angle||35deg||Crown Depth||12in|
The party was skinning up from the lake on the backside of Microdot on the right side looking up from the lake. The top skier triggered the avalanche right at the spot where the cornice was starting to form on the right hand shoulder of the ridge. The side we were skinning up was the leeward side of the mountain and had accumulated a slab which measured about 1.5 feet thick at the right side looking up and about 1 foot thick to .5 feet thick on the left. The avalanche was a classic hard slab avalanche with a compacted faucet base surface and about 35 deg slope. The slope had already been skied multiple times. The crown face extended about 100 ft going from 1.5 ft thick on the right to about .5 ft thick on the left side. Two skiers who where below the trigger point got caught in the slide and rode down the slope approximately 50 ft, ending up sitting up with only the legs buried. One skier got caught at the bottom of the slide and was knocked over. There were no injuries and only 3 ski poles lost.
Obvious signs of instability
|Recent Avalanches?||No||Collapsing (Whumphing)?||No||Cracking (Shooting cracks)?||Yes|
I did not see any new avalanches that day and did not observe any whumphing until this avalanche went off. There were shooting cracks observed. We were all aware that Hatcher's snow conditions have been very avalanche prone this year. There were multiple tracks observable before we skied down and the entire party of 6 skiers made in down the slope with no incident. Just goes to show that you can never tell. Apparently no one had yet tried to cross the place on the top of the ridge where the cornice was starting to form. This was in hind sight obviously a very tender trigger spot.
About 4" new snow, no appreciable wind approx 50 Deg F.
4" fresh on top of a hard packed slab.
Did not dig a pit. The observation of the avalanche showed 4" of fresh snow on top of a compact slab from .5 to 1.5 feet thick on top of a 3 to 4" layer of compacted sugar snow.