According to the North Carolina State Climate Office, thunderstorms typically are 15 miles or less in diameter and last an average of 20 to 30 minutes. Downbursts and straight-line winds associated with thunderstorms can produce winds of 100-150 miles per hour – enough to flip large trucks and endanger airplane landings and takeoffs. Downburst activity from a severe thunderstorm caused major damage to a home in the Kernersville area in 2006.
The National Weather Service considers a thunderstorm severe if it produces hail at least an inch in diameter, has winds of 58 miles per hour or greater, or produces a tornado. Of the estimated 100,000 thunderstorms in the United States each year, only about 10% are classified as severe.
Lightning, a major threat during a thunderstorm, is responsible for more deaths each year in the United States than are tornadoes. Since lightning strikes are very unpredictable, the risk to individuals and property can be significant.




