we get them both
Shelf Clouds probably two or three times a year , you'll seldom get a tornado out of a shelf cloud , but when they pass over the temp drops about 20 to 30 degrees , and well get wind gusts up to 75-85 MPH , for about 10 minutes , then followed by heavy rain
Wall Clouds , we get a bunch of these a year , pretty common , these are the ones that will spawn tornados , but that doesn't mean every wall cloud WILL spawn a tornado , just that you need to keep a close eye on them , not sure how many Wall Clouds we get a year , a dozen at least , probably more , when you live with them every year , you really don't pay much attention
the scariest part about tornadoes , is that often times , they happen at night , after dark , and you can't see anything
