However , an El NiÃ o event , combined with the presence of the Saharan Air Layer over the tropical Atlantic Ocean , contributed to a slow season and forcing all tropical cyclones to dissipate after October 2 . But activity was slowed by a rapidly forming El NiÃ o event in 2006 , the presence of the Saharan Air Layer over the tropical Atlantic , and the steady presence of a robust secondary high pressure area to the Azores high centered around Bermuda . There were no tropical cyclones after October 2 .