Roll Clouds

Vero Beach
NoLL

A Roll Cloud Over Uruguay

Credit & Copyright: Daniela Mirner Eberl

Several times at sea we've seen roll clouds like this one. We don't call them roll clouds, we call them approaching cold fronts. Seeing it come at you is pretty scary. We know that as it passes we will experience very strong winds, and abrupt changes in wind direction.

The usual action to perform is to drop all (or almost all) the sails and tie them down and then tie down the boom. A few times I screwed up and didn't do that, much to our regret. My excuse is that the appearance of the front in the sky is usually not so distinct and clear as the example in the picture. Sometimes I fail to recognize them.

Once, in the Florida Everglades, I recognized it but stupidly concluded that it would not be severe. I wrote about that in this blog post. That post attracted the attention of a weather man in the National Hurricane Center in Florida. He wrote:

"We lose more sailors in Florida waters due to frontal passage wind-shifts than from almost any other cause. I don't mean "can't find", I mean DEAD! Regardless of the situation it is prudent to set a "preventer" on the boom whenever a front approaches. "