Thunderstorms have been defined by the National Weather Service as lightning and thunder present around the rain clouds that produce electric charge. Winds should be more than 58 miles per hour in a thunder storm.
Thunder storms are caused when the hot and moist air in the rain cloud rises in large volume and increased velocity. The outside temperature falls quickly and as the water vapors turn into liquid and the liquid turns into hail, the updraft is stoked and turbulence is caused within it. This results in the cumulonimbus to explode and electric activity along with rainfall starts.