How Do Thunderstorms Happen?

Thunderstorm Ingredients

• All thunderstorms require a few key ingredients -- moisture, which is necessary to form the clouds and rain, unstable air that is warm and will rapidly rise and lift which can come from weather fronts, the ocean shore or mountains. Thunderstorms are formed by cumulonimbus clouds and result in wind gusts, heavy rain, lightning, thunder and sometimes hail. However, there can be thunder snow storms, or snow showers accompanied by thunder or lightning.

Process

• Thunderstorms form as warm air rises as the sun heats the surface of the earth and, in turn, the earth's surface heats the air just above it. Cold air will sink, which is known as convection. Lightning is an electrical discharge between clouds or cloud and earth. Friction occurs when ice and water particles within clouds build static electricity. Positive charges build up on the ground beneath the cloud, particularly around tall objects like trees, mountains, even people and when the charge from the cloud meets the ground charge, lightning happens. The thunder is a sound wave that results from lightning.

Types

• There a few different types of thunderstorms. Orographic thunderstorms are storms caused by air lift coming off the sides of mountains. Air mass thunderstorms form when localized convection occurs in an unstable air mass. Frontal thunderstorms flare up along the borders of different weather fronts, such as a cold front.

Supercells

• Supercell thunderstorms produce the most dangerous storms of all. They happen when strong updrafts meet strong downdrafts, creating a long-lasting storm of intensity. Strong storms can result in flash flooding, hail or even tornadoes. A severe thunderstorm is categorized as a storm producing damaging winds in excess of 58 miles an hour, or hail which is at least 3/4 inch in diameter.