OLogy Cards > hurricanes

In satellite images of Earth's atmosphere, it's easy to spot the large, spiraling clouds of hurricane. These powerful storms are fueled by warm seawater, so they form over oceans near the equator. They can become larger and stronger as they cross the tropical seas. What you can't see in a satellite picture is the hurricane's incredible power. For a storm to be a hurricane, its winds must be blowing more than 74 miles (120 km) per hour.