Part 1 of Essay
get their start over the warm tropical waters of the North Atlantic Ocean near the equator. Most appear in late summer or early fall, when sea temperatures are at their highest. The warm waters heats the air above it, and the updrafts of warm, moist air begin to rise. Day after day the fluffy cumuli form atop the updraft ....

Part 2 of Essay
.... replace the air soaring upwards in the thunderheads. The air begins swirling around the storm center, for the same reason that the air swirls around a tornado center. As this air swirls in over the sea surface, it soaks up more and more water vapour. At the storm center, this new supply of water vapor gets pulled into the thunderhead updrafts, releasing still more energy as the water vapor condenses. This makes the updrafts rise faster, pulling in even larger amounts of air and water vapor from the storm's edg ....