More than 80 avalanches have been observed since a major snowstorm pounded much of Colorado last Tuesday, nearly half of them capable of burying someone, according to the Colorado Avalanche Information Center.

Two were rated large, one near Red Mountain Pass and the other at Wolf Creek Pass, both in southern Colorado. Of the 82 avalanches reported to the CAIC, 40 occurred naturally, 17 were the result of avalanche control work and 20 were caused by skiers, snowmobiles or snowshoers. Most of those were harmless slides, and no one was caught in them. Colorado avalanches killed eight last year but none so far this year.

“What’s happened is we had a lot of early-season snow in October,” said Mike Cooperstein, a forecaster for the CAIC. “That snow turns into weak snow that’s not bonded well to the crystals around it. You end up with this really weak snow on the ground and it keeps on going through this cycle. Eventually, you get what happened (last week), you get a big storm, you put a bunch of weight on top of it, you have a slab on top of a weak layer and you see avalanches. Until these recent storms, we haven’t had that slab, we just had weak crystals sitting on the ground.”

Read the full story at The Denver Post.