What are the characteristics of a squall line?

A squall line is characterized by a line of severe thunderstorms that often extends for hundreds of miles. These thunderstorms are typically associated with strong winds, heavy rain, and sometimes hazardous conditions such as hail and tornadoes. The formation of a squall line is indicative of significant weather systems, often occurring along a cold front. As these storms develop, they can create intense downdrafts and gust fronts that lead to notably high winds.

The presence of severe thunderstorms in a squall line distinguishes it from phenomena that involve light rain or calm conditions. For instance, light rain showers and calm weather patterns do not align with the intensity and violent nature of a squall line. Likewise, scattered smaller thunderstorms do not represent the organized, linear structure that is typical of a squall line. Thus, the correct choice accurately reflects the nature of squall lines in meteorological contexts.