Tue Nov 19 18:16:36 UTC 2024: ## Global Weather Agencies Miss the Mark on La Niña Prediction

**NEW DELHI, November 15, 2024** – Global weather agencies, including the US National Oceanic Atmospheric Administration (NOAA), have significantly underestimated the development of the La Niña weather pattern, defying typical seasonal predictions. While La Niña events usually emerge between April and June, reaching peak intensity between October and February, this year’s forecast proved inaccurate.

Agencies predicted La Niña’s arrival following the strong 2023-24 El Niño, expecting it to persist through the Northern Hemisphere winter of 2025. However, the Oceanic Niño Index (ONI), the key indicator, has not consistently fallen below the -0.5°C threshold required for La Niña confirmation. While briefly reaching this mark, it has reverted to warmer conditions, leading to uncertainty about the event’s strength and duration.

This unexpected development contrasts with earlier predictions of harsh boreal winters and bountiful winter rainfall associated with La Niña. Skymet Weather, citing weak correlations between La Niña and Indian subcontinent weather, and the shallow depth of cooler water during La Niña compared to El Niño, had already expressed skepticism about these forecasts. Historical data further supports their concerns, showing below-normal winter rainfall in most La Niña years over the past two decades.

The current situation indicates a weak, potentially truncated, La Niña at best. The possibility of no La Niña event at all remains a realistic scenario. Even if La Niña does develop, it is expected to be a borderline event lasting only through January and February 2025, with neutral conditions likely returning by early spring.

While the Indian Ocean Dipole (IOD) shows a negative trend, the forecast skill remains poor beyond one month. The Madden-Julian Oscillation (MJO) suggests a potential increase in tropical cyclone development, but model predictions for storm formation are currently low (20-40%). The overall uncertainty highlights the challenges of accurately predicting complex weather patterns like ENSO in a changing climate, underscoring the need for ongoing research and improved forecasting models.

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