JACKSONVILLE, Fla. – The El Niño Southern Oscillation, also known as ENSO is one of the indices we use to help forecast the weather pattern months down the line.
ENSO is a climate pattern of shifts in the tropical Pacific Ocean sea surface temperatures and winds. These shifts often change rainfall and wind patterns around the globe.
After being in a La Niña pattern this winter, things will likely change as we head into spring and summer.
This past year has been extremely dry. In fact, from late August through early February, it’s the second driest stretch on record since the late 1800s. This is common during a La Niña.
Colder waters in the Pacific push the jet stream northward. This tends to lead to drought in the southern U.S. and above-average rainfall in the Pacific Northwest and Canada.
The official NOAA CPC ENSO probabilities show a 75% chance of a transition to a neutral phase through late spring. When we’re in the neutral phase, it means the Pacific Ocean isn’t strongly warmer or cooler than normal. There’s no clear push from either El Niño or La Niña.
What does that mean for our weather?
Typically, above normal rainfall and above normal temperatures can be expected across the Southeast in a neutral pattern.
However, when looking at the end of the forecast, models are beginning to favor a transition to El Niño late spring into the summer. In other words, the probability of that happening is increasing.
El Niño is a phase where warmer-than-average sea surface temperatures are present in the central and eastern equatorial Pacific.
Above normal rainfall is common during El Niño due to the position of the Pacific Jet Stream. This change in pattern would be welcome for our area due to how dry it’s been. Temperatures are generally below normal as well.
But what does this mean during the hurricane season?
When El Niño is present, this would tend to bring fewer tropical systems into the Atlantic basin because wind shear and trade winds are stronger, and there’s more stability in the atmosphere.
We will be sure to continue to monitor the ENSO forecast, as that will give us a good idea as to what our weather pattern will be in the months to come.