What weather event is indicated by the presence of a "wall cloud"?

The presence of a "wall cloud" is primarily associated with the potential for tornado formation. A wall cloud is a localized and vertically oriented lowering of the cloud base that typically forms under a cumulonimbus cloud (thunderstorm). It indicates strong updrafts of air from the thunderstorm that is capable of rotating, which can lead to the development of a tornado if conditions are favorable.

When a wall cloud appears, it can be a sign that the storm is intensifying, often accompanied by increasing wind shear and moisture in the atmosphere, which enhances the likelihood of tornado formation. Observing a wall cloud during severe weather events tends to prompt meteorologists and storm spotters to monitor the situation closely because it can signify an imminent tornado threat. Thus, this characteristic cloud formation acts as a visual cue for potential tornado activity.