La Niña Officially Starts: What to Expect for the Rest of Winter
AUSTIN (KXAN) — The Climate Prediction Center announced Thursday that La Niña has officially started. A detailed analysis found La Niña began in December 2024, with a weak La Niña favored during the rest of this winter.
What is La Niña?
La Niña is the cool phase of ENSO (El Niño-Southern Oscillation) that is marked by sea-surface water temperatures 0.5ºC below the climatological average in a key area of the eastern Pacific.
Those water temperatures reached that key metric in December, marking the long-awaited arrival of La Niña.
La Niña is marked by sea-surface water temperatures in a key area of the eastern Pacific. (Image: NOAA/CPC)
Impact of La Niña
La Niña typically has the greatest impact on the Northern Hemisphere in the winter season as the jet stream or storm track is pushed farther north, keeping it cooler in the Pacific Northwest and Upper Midwest, whereas warmer and drier temperatures are more common in the southern states.
The above photo illustrates a typical La Niña pattern. (KXAN Photo/Eric Henrikson)
Much of the South is currently dealing with or bracing for winter weather. The La Niña pattern doesn’t mean it won’t get cold, wet or wintry. Rather, winter typically is warmer and drier for southern areas.
How Long Will La Niña Last?
This is expected to be a short-duration La Niña, with an ENSO Neutral pattern (neither cool nor warm phase) expected to return in the March-May period.
What About the Rest of 2025?
While forecasting climate patterns like ENSO, they become more complicated before the spring season is completed.
ENSO probabilities are illustrated in a graph from the NOAA/CPC. (Image: NOAA/CPC)
The odds favor ENSO Neutral conditions to continue through summer and into next fall. While Neutral is favored, the odds of another La Niña are substantially higher than the return of El Niño as we head through the fall months.
Conclusion
In conclusion, La Niña has officially started, and it’s expected to have a significant impact on the Northern Hemisphere, particularly in the winter season. The good news is that it’s expected to be a short-duration La Niña, with an ENSO Neutral pattern expected to return in the spring.
FAQs
Q: What is La Niña?
A: La Niña is the cool phase of ENSO (El Niño-Southern Oscillation) that is marked by sea-surface water temperatures 0.5ºC below the climatological average in a key area of the eastern Pacific.
Q: How will La Niña affect the weather?
A: La Niña typically has the greatest impact on the Northern Hemisphere in the winter season, keeping it cooler in the Pacific Northwest and Upper Midwest, whereas warmer and drier temperatures are more common in the southern states.
Q: How long will La Niña last?
A: This is expected to be a short-duration La Niña, with an ENSO Neutral pattern (neither cool nor warm phase) expected to return in the March-May period.
Q: What about the rest of 2025?
A: The odds favor ENSO Neutral conditions to continue through summer and into next fall. While Neutral is favored, the odds of another La Niña are substantially higher than the return of El Niño as we head through the fall months.
