Tropical cyclones are large whirling storms that obtain their energy from warm ocean waters. They stand out on satellite images due to their circular cloud patterns and, in the stronger storms, a nearly clear eye at the center. The clarity and size of the eye on satellite images help meteorologists estimate a cyclone's strength.

A tropical cyclone is a large low pressure system without any "front" attached. Tropical cyclones develop over the tropical or subtropical waters near the equator and have different names depending on where they form:

• In the Atlantic/Eastern Pacific Oceans - hurricanes
• In the Western Pacific - typhoons
• In the Indian Ocean - cyclones

This module will focus on hurricanes, or tropical cyclones that form primarily in the Atlantic basin which includes the North Atlantic Ocean, the Gulf of Mexico, and the Caribbean Sea. The Hurricane season in the Atlantic basin starts on June 1st and ends November 30th but hurricane activity typically peaks in September when the ocean is warmest.