What is the primary hazard associated with thunderstorms?

The primary hazard associated with thunderstorms is low ceiling and visibility. Thunderstorms can produce heavy rainfall, which dramatically reduces visibility, making it particularly hazardous for pilots and drivers. Additionally, the clouds in thunderstorms can form cumulonimbus clouds, which are often associated with low ceilings and reduced visibility due to precipitation and cloud cover.

While destructive straight-line winds are indeed a significant hazard during thunderstorms, they are not always present, and their impact is typically localized. Excessive icing conditions can occur in some thunderstorms, especially at higher altitudes and if the conditions are right, but it is not as prevalent or as immediate a concern as low visibility. Rapid temperature changes can occur in the vicinity of thunderstorms, particularly with downdrafts, yet this is not the primary hazard that causes the most widespread concern.

Thus, low ceiling and visibility are consistently recognized as the most critical hazard in thunderstorms, impacting safety for various activities such as aviation and driving.