What characterizes a Squall Line?

A squall line is characterized by a long line of thunderstorms that are typically associated with severe weather conditions. These squall lines can extend for many miles and are often seen ahead of a cold front, producing strong winds, heavy rain, and sometimes even severe weather phenomena such as hail and tornadoes.

The defining feature of a squall line is its structure as a continuous line of active convection, where multiple thunderstorms can be located in a straight formation. This means that rather than being isolated storms, they are part of an organized system that can lead to significant weather impacts over a substantial area.

In contrast, a single thunderstorm, weak rain showers, or a series of dry fronts do not capture the essence of what constitutes a squall line, as they lack the continuity and typically intensified weather characteristics that define the squall line phenomenon.