Meteorology: Understanding the Atmosphere            Ackerman and Knox

The overshooting top is a domed-structure of a thunderstorm that extends above the anvil, often into the stratosphere. In the visible image below, note the smooth, spreading cloud layer that comprises the storm anvil. The overshooting top is the cauliflower cloud structure extending above the anvil like a dome. Overshooting tops locate the updraft near the top of the storm.