Hurricanes form when a pre-existing disturbance, accompanied by thunderstorms, develops over an ocean that is at least 81 degrees Fahrenheit to a depth of 150 feet. Those warm waters provide a tremendous source of fuel for the storm.

Under the right conditions, the developing storm can become a serious tropical cyclone provided the winds aloft (follow this animated link to see how ocean winds are measured today) are light and have a low wind shear. (A heavy upper wind, with high wind shears, can remove the tops of thunder clouds. That action stops the tropical depression from becoming a hurricane.)

Although tropical cyclones develop in both the Pacific and Atlantic Oceans, Cape Verde storms occur within the Atlantic’s Hurricane Alley. (You will need QuickTime for this link.) Pushed west by the prevailing Easterlies, the storms spawned near Cape Verde can track toward land or remain at sea in any given season. (Follow this amazing link to view animated tracks from a half-century of major storms.)

When Africa experiences drought, fewer Cape Verde storms develop. But when rains are heavy, the hurricane season is more intense. "Category 5" is the term meteorologists use to describe the worst types of hurricanes. "Monster" is one of the terms survivors use.

People in Galveston used those words - and many others - the day the sea swallowed their city.