Glide cracks are very easy to see, but difficult to predict.
They don’t always avalanche. When they do, they fail all the way
to the ground. Sometimes they avalanche when its storming,
sometimes they avalanche when its warm, sometimes they avalanche
during cold snaps.
Treat glide cracks like cornices and stay away from them. Don’t
travel underneath them. They avalanche for random reasons at
random times. The good news is that they are easy to avoid
because you can see them.