During a thunderstorm, you're most likely to get sleet rain and hail.
A thunderstorm is a storm consisting of thunder and lightning. A thunderstorm is produced by a cloud known as a cumulonimbus and it is usually accompanied by sleet rain, hail, strong winds or no precipitation at all. Thunderstorms are considered to be severe when it contains either wind gusts above 50 knots, or a tornado or hail of one inch or greater.