How is the beginning of a thunderstorm reported?

Thunderstorms are characterized by the presence of both thunder and lightning. When reporting the beginning of a thunderstorm, it's essential to note that both phenomena must be observed to classify it as an official thunderstorm. The presence of thunder indicates that the storm is producing electrical energy, while lightning is a visual manifestation of that energy.

Simply hearing thunder or observing lightning independently does not fulfill the criteria for a thunderstorm report. Thunder can sometimes be heard without visible lightning, particularly at a distance from the storm or when certain atmospheric conditions exist. Thus, the simultaneous observation of both thunder and lightning is what defines the onset of a thunderstorm. This ensures accurate communication and awareness of storm activity, which is crucial for safety and operational purposes in aviation and meteorology.