The linked article above had a nice summary for El Niño and La Niña, which I've pasted into this blog post. See below:
El Niño and La Niña are common meteorological terms that we expect to hear for seasonal hurricane forecasts — and with good reason. A strong El Niño or La Niña has a significant impact on hurricane development.
El Niño is a naturally occurring phenomenon characterized by warmer than normal water in the eastern Pacific equatorial region. While El Niño occurs in the Pacific Ocean, it has widespread impacts on the global climate. One of the elements is increased wind shear across the tropical Atlantic, which creates hostile conditions for hurricane development.
La Niña is the opposite of El Niño, characterized by cooler water in the eastern Pacific equatorial region. When La Niña is present, conditions tend to be more favorable for hurricane development in the Atlantic.
Currently, we are in a weak La Niña, but the forecasters at Colorado State believe we will transition to a neutral phase of El Niño-Southern Oscillation over the next several months (no El Niño or La Niña).
Lastly, we tend to think of hurricanes as being late summer, but they actually peak a bit later. See the chart below for how they map out on an annual calendar:
Hurricane season 2018 is forecast to be above average