Thunderstorms, some severe, may produce heavy to excessive rainfall and isolated flooding over portions of the Southern Plains through Saturday. Widespread showers and thunderstorms will spread east into the Great Lakes, Ohio Valley, Mid Atlantic and Northeast. Dry conditions, combined with gusty winds will continue to support an elevated fire weather threat in the Desert Southwest. Read More >
Thunderstorm - A rain-bearing cloud that also produces lightning.
All thunderstorms are dangerous. Every thunderstorm produces lightning. In the United States, an average of 300 people are injured and 80 people are killed each year by lightning. Although most lightning victims survive, people struck by lightning often report a variety of long-term, debilitating symptoms. Other associated dangers of thunderstorms include tornadoes, strong winds, hail, and flash flooding. Flash flooding is responsible for more fatalities—more than 140 annually—than any other thunderstorm-associated hazard.
Dry thunderstorms that do not produce rain that reaches the ground are most prevalent in the western United States. Falling raindrops evaporate, but lightning can still reach the ground and can start wildfires.
Above information borrowed and edited from FEMA publication:
https://www.fema.gov/hazard/thunderstorm/index.shtm