Find out what fueled one of the worst hurricane seasons in history.
By the numbers the 2005 Atlantic tropical storm season was unlike any other: A total 27 tropical storms, including 15 hurricanes, made it a record-breaking year. The season also gave rise to Katrina, one of the most intense and costliest hurricanes that resulted in 1,200 deaths and more than $100 billion in damages. The unusually high frequency and strength of these tropical storms were linked to favorable development conditions observed in the ocean and atmosphere between the Caribbean Sea and west coast of Africa where they form. Easterly winds blowing off the African continent seeded the Atlantic with a large number of proto-hurricanes—swirling air masses that grow over tropical waters. Ideal open ocean wind patterns on the surface and high above permitted storm clouds to easily mature into vigorous convective cells—the building blocks of hurricanes. Warmer ocean surface waters slightly above their 80 degrees Fahrenheit average further strengthened the storms and sent the spinning hurricanes into overdrive. The visualization below tracks the paths of all 27 tropical storms that made up this historical year.