Thunderstorms form when the three required atmospheric conditions of sufficient moisture, unstable air and a lifting mechanism are present. In the United States, thunderstorms are most common in the spring and summer mon... More »

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Thunderstorms are formed by the combination of three main ingredients: moisture, unstable atmospheric air and an external acting force making the damp and volatile air rise upward. Thunderstorms come in several different... More »

According to the National Severe Storms Laboratory, thunderstorms occur most frequently in temperate climates where warm, moist air encounters pockets of cool air. The four categories of thunderstorms are single-cell sto... More »

Tornadoes form out of thunderstorms, where moist air rises, cools and condenses into clouds that release heat and force cooler air back down. If the updrafts are strong enough, the feedback loop forms an air vortex that ... More »

Most tornadoes are created as a result of thunderstorms that form at the meeting point between humid air from the Gulf of Mexico and dry, cooler air from Canada. At that point, instability occurs in the atmosphere, and a... More »

Hurricanes are massive storms made out of an organized series of thunderstorms that form over the ocean. Typhoons are the same as hurricanes, except they occur in a different part of the world. Tornadoes are smaller stor... More »

Tropical cyclones, including hurricanes and typhoons, form when calm, warm ocean waters set up a spiraling convection current in the air above the surface. As warm, moist air rises, cooler air moves in to replace it, cre... More »