Tornadoes are only a small piece of a much larger picture. Learn what features are frequently found in thunderstorms that give birth to tornadoes:

Anvil
Thunderstorms form when updrafts cause cumulus clouds to grow into towering mountains called cumulonimbus clouds. At 35,000-50,000 feet a growing storm cloud typically hits a layer in the atmosphere called the stratosphere, which acts like a ceiling. This forces the cloud to spread sideways and form a distinctive anvil shape.

Wall Cloud
Tornadoes tend to form under a wall cloud, although there is no wall cloud in this particular image. A wall cloud is a smaller cloud underneath the main cloud. It is relatively free of precipitation and sometimes helps storm spotters visually identify where a possible tornado might hit the ground.

Precipitation
Precipitation follows a fairly specific pattern, from left to right in this picture: Light rain gives way to heavy rain, then to light hail and, finally, to large-sized hail. Generally, the wall cloud area around the tornado is precipitation-free, although in this particular storm, hail was falling behind the tornado.

Flanking Line
The back of a massive thunderstorm usually has a flanking line of stair-like cumulus cloud towers. The wall cloud is usually found underneath the area where the flanking line intersects the tallest-growing tower in the storm.