Which weather phenomenon is always associated with a thunderstorm?

• A. Lightning
• B. Thunder
• C. Hail
• D. Rain

Answer: (A)

Electrical discharge in a cumulonimbus cloud is what defines a thunderstorm. The storm builds up strong electrical charges as the air rises and separates, and that energy must be released as lightning. The rapid heating and expansion of air from the lightning then creates the thunder you hear. Rain and hail often accompany thunderstorms, but they aren’t guaranteed—some storms may produce little or no hail and even rain that doesn’t reach the ground. Because the electrical discharge is a fundamental, universal feature of a thunderstorm, lightning is the weather phenomenon that is always associated with it.