What is El Nino
El Nino is a naturally occurring phenomenon which causes the waters in the Pacific ocean to warm north of the equator. It occurs in cycles between 2 to 7 years, with 5 years being the average. The images below show how the wind patterns are effected.
El Nino effects on hurricane season
In the Atlantic El Nino increase the vertical wind shear which works to decrease hurricane formation and strength by causing the west winds to influence weather patterns. El Nino also causes a drier hurricane season farther decreasing hurricane formation and strength. Records show that El Nino does not seem to have an effect on the number of hurricanes or intensity in the Pacific but does shift the hurricane path eastward.