Deep Persistent Slab avalanches are scary. Their consequences are ultimate. They are unsurvivable. In addition, they are fickle and hard to predict. Your best bet is to avoid where they could happen, which are large avalanche paths that did not run huge in March.

The pattern is pretty clear. During our historic first two weeks of March, these huge avalanches ran from large alpine and near treeline avalanche paths, on all aspects. The snowpack structure that led to these avalanches remains in place on many slopes that did not avalanche in March. You can recognize these slopes that have not avalanched by their smooth and deep looking snow cover. When you compare the lack of avalanche evidence on these to the slopes that did slide, it's not too difficult to distinguish which is which. Grey skies and flat light today may obscure the picture, so if in doubt, assume it hasn't gone yet.

The slopes that did avalanche are easy to identify given a few key observations. They have deep debris piles near the bottom of the paths, many chock-full of broken trees. In the start zones, the crowns of snow above these old avalanches remain visible. Depending upon when the big avalanche released, you'll find none to several feet of snow deposited on the old bed surfaces. So far, we've received no reports of avalanches on the March bed surfaces. In general, there the basal weak layers in these paths are dramatically disturbed, and the fledgling slabs not very stiff. It's worth investigating the potential of a thinner Persistent Slab avalanche on one of these bed surfaces, but to the best of our knowledge there's been no slab avalanches running again on the slopes that released in early March.

The Deep Persistent Slab avalanche problem is not as prevalent on the Grand Mesa or anywhere below treeline. Although it has become unlikely for you to trigger a deep avalanche, it is not impossible in isolated terrain features. Wet loose snow sluffing is the primary concern. You can easily manage these types of problems by moving onto shady, cooler slopes as the snow begins to warm.