What typically indicates a severe thunderstorm?

Severe thunderstorms are typically characterized by the presence of very frequent lightning strikes. This occurs due to the intense updrafts and downdrafts within the storm that create a highly charged environment. As moisture-laden air rises rapidly, it cools and condenses, leading to the formation of ice particles and water droplets that collide and generate electrical charges. This results in an often dramatic display of lightning, making it a key indicator of the intensity of the storm.

In contrast, the presence of cirrus clouds does not indicate severe weather; instead, these high-altitude clouds often precede warm fronts and signify fair weather. Heavy rainfall with little lightning can occur in some storms but does not necessarily indicate severity, as some thunderstorms produce rain without intense electrical activity. Lastly, stable atmospheric pressure suggests calm weather conditions rather than the instability that fosters severe thunderstorms. This stability can inhibit the formation of the powerful updrafts necessary for such storms, further highlighting why frequent lightning is a significant signifier of severe thunderstorms.