Mike the Strike wrote:
.../..

I was driving in Idaho last February in snow showers and there were
snow devils that looked just like our summer dust devils. I suspect
that winter thermals might be more common than we think.

Slightly off topic, but....

Many years ago I wanted to check the still air trim of a F1A towline
glider, so when I woke up to see still air and a couple of inches of
snow I thought the time had come, grabbed the model and headed for the
park for a quick before work session. Wrongo: there were thermals a
plenty over the snow. It was fun, but the still air trimming session
didn't happen.

The park was Clapham Common. We don't get much snow in London, hence the
excitement.

--
martin@ | Martin Gregorie
gregorie. |
org | Zappa fan & glider pilot