Thunderstorm over Garajau, Madeira

Thunderstorms are small, intense weather systems that make strong winds, heavy rain, lightning, and thunder. Thunderstorms can happen anywhere with two conditions: the air near the Earth's surface must be warm and moist (with lots of liquid), and the atmosphere must be unstable. 100 lightning bolts hit the earth every second, and at any one moment, about 1,800 thunderstorms happen around the earth.

Thunderstorms are rare in winter, mostly because of cold weather. When they happen, it is called thundersnow. Thundersnow is common in blizzards.