As we have mentioned in our past evaluations of the El Niño’s significance in the summer and fall, we are back again to analyze the wintertime impacts of a developing El Niño on New Jersey weather. An El Niño occurs when warmer-than-average waters exist in the central and eastern Pacific Ocean, specifically near the equatorial latitudes.

Early this past summer, we reported on the potential impacts of a developing El Niño event in the tropical Pacific on summertime weather in New Jersey. While El Niños can impact the weather worldwide, we found that New Jersey's weather doesn't fluctuate with an El Niño event. This year's summer (June-August) proved to be rather comfortable, with the statewide average temperature 0.8° below the 1981-2010 average , and precipitation 0.26” above the 1981-2010 average.

As climatological summer and the Atlantic hurricane season begin on June 1, scientists are carefully monitoring sea-surface temperatures in the tropical Pacific Ocean for a potential El Niño event. An El Niño occurs when warmer-than-average waters start to form in the eastern Pacific Ocean, specifically near the equatorial latitudes. Easterly winds (blowing from the east) typically move warmer water to the western Pacific (near Indonesia), permitting cooler water to upwell to the surface in the east (near South America).