La Niña is finally here: What this weather event means for winter in the U.S.

STATEN ISLAND, N.Y. — The National Weather Service’s Climate Prediction Center reports that after a lengthy wait, La Ni a conditions are finally here. However, what impact does this weather phenomenon have on the weather in New York?

One needs to have a basic understanding of the ENSO cycle in order to comprehend La Ni a.

According to the weather service, the El Ni o-Southern Oscillation (ENSO) cycle is a recurrent climatic phenomenon related to variations in the water temperatures out in the central and eastern tropical Pacific Ocean.

Over time, the surface waters in some parts of the Pacific have a tendency to warm or cool. The weather service refers to that variation as the ENSO cycle.

According to the weather service, ENSO-neutral conditions occur when neither of the ENSO cycle’s severe phases—El Ni o or La Ni a—are present. The Pacific Ocean’s sea surface temperatures are close to normal during this neutral period.

In contrast to El Ni o, La Ni an is a frigid occasion. According to the National Oceanic and Atmospheric Administration (NOAA), trade winds are strengthened at this stage of the cycle and push warm water toward Asia, which cools the waters off the West Coast. Temperatures are often colder in the North and warmer in the South when this occurs and La Nia takes over for the winter.

La Ni a and its forecast impact

Despite predictions for a transition to La Ni a, ENSO-neutral conditions persisted for several months.

The current La Ni a conditions are predicted to last until February-April 2025 (59% chance), after which they are anticipated to shift to #ENSO-neutral in March-May 2025 (60% chance). There is now an A#LaNinaAdvisory in force.J3OSrwmH1w https://t.co/5zlzaZ0D9Zpic.twitter.com

After much delay, the Climate Prediction Center reports that below-normal sea surface temperatures (SSTs) in the central and east-central equatorial Pacific Ocean were a result of the emergence of La Niña conditions back in December.

Given La Niña, one would wonder how this would affect the weather in New York. Not only would temperatures be affected if this were a normal La Ni a, but storm patterns might also be affected, leading to a more northern track throughout the winter.

But according to the institute, forecasts still suggest that this will be a weaker La Ni a, which is less likely to produce typical winter/spring impacts. However, the Climate Prediction Center staff points out that prediction guidance may still be influenced by predictable signals.

According to the Climate Prediction Center, as of Jan. 9, there is a 59% possibility that La Niña conditions will continue through some point between February and April. The likelihood that ENSO-neutral conditions would reappear sometime between March and May is 60% after this.