I'm the weatherman now!

I've always been a smart guy, at least that's what my girlfriend says. Or did she say I was smart for a guy? Mmmm. Anyhow I'm a very keen observer of everything around me, except for that time I set myself on fire, but that's another story. Well, what I was trying to say was that I noticed that when the wind blows from one direction steadily and changes direction slowly the grass will sweep a semicircle in the sand. As the wind changes direction slowly it fills in the pattern and makes it in a different spot but it's still a semicircle. A semicircle is a portion of a circle and has nothing to do with large trucks. Now for the good part. The weather is pretty tame when this is happening. Now for the bad part. When the wind shifts fast enough to make a full circle and not fill in the part it made before it's time to pack up and leave because something bad weatherwise is on the way. At least that's what happened everytime this phenomenon occurred. The funny part is I'm too stubborn to leave until I can't see through the snow or rain. Think I'd learn after a few applications wouldn't ya? God bless.
Mark