Thunderstorm Formation. A thunderstorm forms when warm, humid air rises rapidly within a cumulonimbus cloud. Thunderstorms have warm temperatures, moisture, and rising air, which may be supplied by a low-pressure system.
Thunderstorms have a three-stage life cycle: the cumulus stage, the mature stage, and the dissipation stage.
In the mature stage, heavy winds, rain, and lightning dominate the area.
In the dissipation stage, updrafts stop, winds die down, lighting ceases, and precipitation weakens.
Tornadoes can form when warm, humid air rises rapidly in thick cumulonimbus clouds—the same type of clouds that bring thunderstorms.
Tornadoes in the U.S. are most likely to occur in a region known as Tornado Alley.
What conditions are needed????
In a hurricane, air moves rapidly around a low-pressure area called the eye.
Warm, humid air rises and begins to spiral
As air rises, more warm, moist air is drawn into the system, and the hurricane gains energy
As winds spiral inward, bands of high winds and heavy rains form.