A storm accompanied with lightning and thunder.
A cumulonimbus cloud that is accompanied by lightning and thunder, or for automated systems, a storm detected by lightning detection systems.
(cumulonimbus) - the towering cumulus cloud has continued to grow in height and width and now lightning is occurring. The storm may extend 5 to 10 miles high into the atmosphere and 5 to 25 miles across. Heavy rain and gusty winds often accompany the storms.
Sudden electrical discharges manifested by a flash of light (lightning) and a sharp rumbling sound. Thunderstorms are associated with convective clouds (Cumulonimbus) and are more often accompanied by precipitation. They are usually shortlived and hit on only a small area.