Austin (Kansan) — The La Niña phenomenon occurred this winter, Climate Prediction Center That's what they said in their latest outlook released Thursday, but it might not be such a big threat after all.
La Niña occurs when sea waters in the eastern equatorial Pacific Ocean become at least half a degree cooler than average. This is the opposite of El Niño, when the same waters become warmer than average.
This year, La Niña is expected to officially begin sometime between now and November. There is a 77% chance that La Niña will continue into winter (December-February), but it is not expected to last long beyond 2025.
The Climate Prediction Center described the current La Niña outlook as “weak and short-lived” and said it would influence future winter forecasts.
Weak La Niña impacts winter
La Niña typically makes North American winter patterns relatively predictable, but the strength of La Niña affects that predictability.
Remember, a typical La Niña event would result in drier, warmer weather for most of the southern states and wetter, cooler weather for many of the northern states. Pacific jet stream Usually it is further north.
But a weakening La Niña “will make traditional winter impacts less likely, although predictable signals may still influence forecast guidance,” according to the latest outlook.
That means the winter outlook will only broadly resemble the map above: Southern states may still be dry and warm, but not necessarily too far off average. Similarly, the Pacific Northwest and Ohio Valley may see wetter than normal conditions, but the forecast is murky.
A weakening La Niña essentially means that without the usual influence of a strong El Niño or a strong La Niña, it may become more difficult to establish the accuracy of winter forecasts.
When will La Niña end?
This “short-lived” La Niña event is expected to begin between September and November and strengthen through the winter.
But it's likely to be gone already by early next year, and the Climate Prediction Center thinks it could be over by spring of 2025.
We can't say much more than that yet. The chances of an El Niño event gradually increasing through late spring 2025, but overall remain low.
