AUSTIN (KXAN) — For the first time in a year and a half, we’re no longer in a La Niña phase, according to the Climate Prediction Center.
As a result, the La Niña advisory has ended and the CPC has issued a Final La Niña Advisory, essentially putting a cap on the end of our most recent La Niña period and the third La Niña winter in a row.
La Niña is the “cool phase” of the El-Niño-Southern-Oscillation or ENSO. It’s marked by water temperatures in the eastern equatorial Pacific Ocean cooler than -0.5º C compared to the long-term average. These waters warmed to just -0.4º C compared to normal for the February monthly average, which takes us out of La Niña and into an ENSO Neutral Phase.
Water temperature isn’t the only component to measuring ENSO — how the atmosphere is acting or responding to the warmer or cooler water is also analyzed. There are some lingering signs of La Niña leftover in the atmosphere, but in general, even the atmosphere is trending toward a neutral phase.
As we talked about during last month’s ENSO update, spring is historically a challenging time to make accurate ENSO forecasts for the following winter. ENSO events typically peak in the winter, so as you’re coming out of them in the spring it can be hard to see enough signals in the water or the atmosphere to get a good handle on what will happen during the following season.
There are, still, notable indications that a transition to El Niño is still in the cards later this year.
An ENSO neutral period is favored through the three-month period of June-July-August. ENSO neutral means the temperature of the Pacific Ocean wouldn’t have a quantifiable impact on the weather we see in North America.
By July-August-September, El Niño becomes the favored phase of ENSO with more than 60% odds of El Niño by August-September-October and carrying over into early winter 2023-24.
According to the NOAA ENSO Blog, we’ve never gone five years without El Niño and right now we’re into year four.
What would El Niño mean?
La Niña makes for warmer and drier winters here in Central Texas, but El Niño does the opposite. A wetter and cooler winter would potentially help us with our drought but could also bring more flash flooding events to the area.
We should have a more definitive idea about what to expect next winter once we get through this spring, where historically, confidence starts to increase.