High Quality Content by WIKIPEDIA articles! The 2011 Atlantic hurricane season was well above average in the number of tropical cyclones that formed, at nineteen. It was also the first time that the first eight tropical cyclones of the season failed to attain hurricane status. Although Tropical Storm Arlene formed on June 28, the season officially began on June 1 and ended on November 30, dates that conventionally delimit the period of each year when most tropical cyclones develop in the Atlantic basin. The season`s final storm, Tropical Storm Sean, dissipated on November 11.