How thunderstorms form
They form when most cumulonimbus clouds form on hot humid afternoons. They also form when warm air is forced upward along a cold front. In both cases the warm humid air rises rapidly. The air cools forming dense thunderheads. Heavy rain falls sometimes along with hail. Within the thunderhead are strong upward and downward winds updrafts and downdraft. But many thunderstorms form in the spring and the summer time in the southern states or on the Western Plains. A thunderstorm is a small storm often accompanied by heavy precipitation and frequent thunder and lightning.
Lightning and thunder
During a thunderstorm areas of positive and negative electrical charges build up in the storm clouds. Lightning is a sudden spark or electrical discharge as these charges jump between parts of a cloud between nearby clouds or between a cloud and the ground . Lightning is similar to the shocks you sometimes feel when you touch a metal objects on a very dry day but on a much larger scale. A lightning bolt can heat the air near it to as much as 30,000 C much hotter than the sun's surface. The rapidly heated air expands suddenly and explosively. Thunder is the sound of the explosion. Because light travels much faster than sound you see lightning before you hear thunder.
Thunderstorms can cause severe damage. The heavy rains associated with thunderstorms can flood low lying areas. Lightning can also cause damage. When lightning strikes the ground the hot expanding air can shatter tree trunks or start forest fires. When lightning strikes people or animals it acts like a powerful electric shock. Lightning can cause unconsciousness,serious burns,or even heart failure.
A major danger during severe thunderstorms is flooding. floods occur when so much water pours into a stream or river that its banks overflow covering the surrounding land. In urban areas floods can occur when the ground is already saturated by heavy rains. The water can't soak into the water logged ground or the many areas covered with buildings,roads, and parking lots. A flash flood is a sudden, violent flood that occurs shortly after a storm.
The safest Place during a thunderstorm is indoors. If you are inside a house avoid touching telephones, electrical appliances, or plumbing fixtures, all of which can conduct electricity. It is usually safe to stay in a car with a hard top during a thunderstorm. The electricity will move along the metal skin car and jump to the ground. However do not touch and metal inside the car. During thunderstorms avoid places where lightning may strike. Also avoid objects that can conduct electricity such as metal objects and bodies of water. How can remain safe if you are caught outside during a thunderstorm? It is dangerous to seek shelter under a tree because lightning may strike the tree and you. Instead find a low area away from trees, fences, and poles. Crouch with your head down. If you are swimming or in a boat get to shore and find shelter away from the water.