the total death toll in a war is soldiers and civilians combined

There is not a specific " Class A" naltural disaster. Natural Disasters are classified by death toll, property damages, etc.

unfortunately not jar-jar binks.jk,but there was a large death toll.

so many people die unless they can predict and have large scale evacuations

There's really no positive thing of tornadoes. The negative things are damage, devastation, the death toll, that they're the strongest of natural disasters.