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. This warming is due to a weakening of winds moving to the west, which typically transport warmer waters to the western Pacific, permitting cooler water to upwell to the surface in the east. When these winds are weaker or if they reverse direction, warm water stays in the east. The warmer sea surface temperatures in the east and the altered atmospheric flow pattern create a new dynamic between the ocean and atmosphere. The newly formed interaction sets up distinct and repetitive weather patterns across the world. No two El Niño events are alike; they vary depending on the magnitude and location of where the largest temperature anomalies are found. However, each one tends to alter weather patterns outside the overall norm.
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. These mild conditions replicated what we expect out of an El Niño summer. Now we’re back to tell you the story for the fall.
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). When these winds are weaker, or if they reverse direction, the warm water stays in the eastern Pacific. This difference in sea surface temperatures and winds creates a new dynamic between the ocean and atmosphere, distinctly affecting weather patterns across the world. No two El Niño events are alike; they vary in magnitude and location of the largest temperature anomalies. El Niño events can be classified as Strong, Moderate or Weak. What might an El Niño summer mean for New Jersey's weather?