This is the beginning of a tornado.
Tornado is a violent, dangerous windstorm occurring over land, that is characterized by a twisting, upturned spinning cone (or funnel shaped) cloud. Tornado starts to develop when there is upward movement of warm air into a region of cold air. The cap of cold air will later fall in, allowing the storm winds to start spinning (rotating) forming a funnel shaped cloud. A tornado has the ability to destroy anything in its path (including buildings) as it moves over the ground.
