Fairly local phenomena though wouldn't you say?
I have also seen a similar situation which I was actually waiting to occur. A weatherman had told us about the weather situation and warned us that the wind WILL change direction during the afternoon and when it does WILL move this air from the sea to the land and the fog WILL form quickly as it does so.
Although the actual change was fairly quick, it was forecast and we were waiting to see it happen.
One could hardly say that was a situation for which we were unprepared.