posted on Apr, 14 2012 @ 07:03 PM
People with better meteorological background then me can feel free to dispute this if its wrong, but my understanding is that tornado’s spawn from
storm fronts (the leading edge). They are the normally horizontal leading edge, that gets pushed down. The rain is in the center of the storm, after
the front, and the whole thing resides in a low pressure system, making it colder. So the cold indicates a pressure system moved in, then you get the
tornado's in the leading edge of the storm front, followed by the rain after the front passed.