An isolated thunderstorm is a type of storm that doesnt cover a large stretch of land, instead dumping rain on a concentrated area. Isolated thunderstorms have less coverage, blanketing a smaller patch of land and affecting fewer people than other types of storms. They tend not to last very long and more rarely cause extreme weather on the ground, though there is still a possibility. Isolated thunderstorms most commonly occur where there are light winds and high moisture at low and middle levels close to the ground. In general, isolated thunderstorms are smaller and cover less area, only affecting about 10-20% of the forecasted area. During an isolated thunderstorm, rain is usually heavy but brief, and lightning is typically infrequent.