What conditions are necessary for a storm to be classified as a "severe thunderstorm"?

A storm must meet specific criteria to be classified as a "severe thunderstorm." These criteria include the presence of high winds, significant hail size, or the occurrence of tornadoes. The correct choice outlines that for a thunderstorm to be classified as severe, it must exhibit winds of 58 mph or higher, hail of 1 inch or greater in diameter, or the presence of a tornado.

This classification is critical because severe thunderstorms can pose significant hazards, including strong winds capable of causing damage, large hail that can threaten crops and property, and tornadoes that can lead to serious destruction. The thresholds set for these criteria ensure that only storms with the potential for impactful weather events are classified as severe, allowing for appropriate warnings and responses to protect lives and property.

In contrast, other conditions such as heavy rainfall or dense fog do not meet the defined criteria for a severe thunderstorm classification, as they do not reflect the high-impact nature of severe weather related to wind and hail. Additionally, lower thresholds, such as winds of 40 mph or 30 mph or hail of any size, also do not indicate sufficient severity to warrant that classification.