Read here and here. Research was done to determine if ENSO events were drivers of hurricane formation frequency and intensity. In addition, the impact of the Atlantic Multidecadal Oscillation (AMO) was investigated. These empirical results basically refute any connection to the non-scientific hysteria that global warming causes more hurricanes.
The peer-reviewed study found that over an extended period (1900-2008), La Niña conditions were strongly correlated to high activity hurricane seasons for the Atlantic and Caribbean basins, regardless of increasing CO2 levels and global warming. Also, it was found that a negative AMO phase in sync with an El Niño period was a combination that severely inhibited hurricane formation.
"...confirmed that "Atlantic basin hurricane activity is significantly reduced in El Niño years compared with La Niña years," and that "the largest impacts of ENSO on large-scale climate fields were shown to be in the Caribbean, with smaller signals observed over the remainder of the tropical Atlantic." He also determined that "the large-scale field that appears to be impacted the most by the phase of ENSO is the 200-850-mb vertical [wind] shear field, with considerably more shear present in El Niño years, especially over the Caribbean." And as would thus be expected, he reports that hurricane "landfalling frequency along the U.S. coastline is less in El Niño years as well,"..."in general, El Niño-La Niña relationships are stronger in the negative phase of the Atlantic Multidecadal Oscillation (AMO) than in the positive phase of the AMO."" [Philip J. Klotzbach 2011: Journal of Climate]
"...determined that "the probability of one or more hurricanes and major hurricanes tracking through the Caribbean increases dramatically from 39% and 26% in the 10 warmest ENSO years to 92% and 63% in the 10 coldest ENSO years, respectively," in harmony with the similar findings of Tartaglione et al. (2003), who additionally demonstrated that this cooling-induced response was likely due to "reductions in vertical wind shear and increases in low-level vorticity" in La Niña conditions...researcher also determined that "the impacts of ENSO are reduced slightly when the AMO is positive," and he found that "a negative AMO phase and El Niño combine to provide large-scale climate features that are especially hostile for tropical cyclones." [Philip J. Klotzbach 2011: Journal of Climate]