Hurricanes are caused by clusters of thunderstorms consolidating together, developing over warm, tropical seawater, typically in late summer. These storms merge together into a spiral shape to form a hurricane. Because intense pressure draws in warm, moist winds towards the center of the storm, this wind spiral upwards and spin faster and faster. The rapidly rising air then cools, forming towering storm clouds and torrential rains. Thunderstorms form in large cumulonimbus clouds which carry water vapor high into the atmosphere where it condensed into hail and ice. The movement of hail and ice in thunderclouds causes an electric charge to build up which zaps down as lightning