La Nina conditions favourable, may form in June-August, says US weather agency
monsoon season that begins in June. "A transition from El Niño to ENSO-neutral is likely in the next month. La Niña may develop in June-August (49% chance) or July-September (69% chance)," NOAA said.
El Niño, Spanish for "little boy," is a climatic pattern marked by elevated sea surface temperatures in the central and eastern Pacific Ocean. This phenomenon typically occurs every 2-7 years, and can last for 9-12 months, influencing global weather patterns. La Niña, meaning “little girl", is characterised by the cooling of sea surface temperatures in the same regions.
It occurs every 3-5 years, and can occasionally happen in consecutive years, leading to increased rainfall and distinct weather patterns. La Niña generally tends to follow strong El Niño events, which also provides added confidence in the model guidance favouring La Niña. "We’ve seen a quick switch from El Nino to La Nina several times before in our 1950-present record, especially after a strong El Nino.
This tendency is one source of confidence in the prediction that La Nina will develop later this year," the US weather agency said. During April 2024, below-average equatorial sea surface temperatures (SSTs) emerged in small regions of the eastern Pacific Ocean. However, above-average SSTs prevailed across the rest of the equatorial Pacific.
The latest weekly Niño index values remained between +0.5°C and +0.8°C in all regions, except for Niño-3 which was +0.3°C.Below-average subsurface temperatures held steady during the month (area-averaged index), with negative anomalies extending from the Date Line to the eastern Pacific Ocean. Low-level wind anomalies were easterly over the western equatorial Pacific, while upper-level winds were near average. Convection
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