2011-12 La Nina Event

The  was a strong one it reached a peak in the Equatorial North Pacific with a 1.9C departure from normal.

2011
The El Niño in 2010 had weakened and dissipated by late March 2011, leaving behind ENSO Neutral and then a developing La Niña which started to strengthen slowly. By early May 2011 it reached moderate strength of -1.2C. Then in mid July 2011 it reached strong status. This gave the Atlantic the advantage as it decreased the Saharan Air Layer and decreased wind shear across that basin. The La Niña eventually peaked at -1.9C in September 2011. Giving the Atlantic an above normal year in terms of tropical cyclone formation.

2012
By early January 2012, the La Niña started to weaken. By June 2012, it had weakened to weak status. Then in July 18, 2012 it had dissipated leaving behind ENSO Neutral. Giving the Atlantic a normal year in terms of tropical cyclone formation.