Note on El Nino: 6th May
A) Detailed Meteorological Note Below this article
C) Simple Note on El Niño : 👇
VAGARIES WEATHER UPDATE
🌊 El Niño – Simple Understanding (May 2026)
👉 Current Status
🟢 ENSO is NEUTRAL
🌡️ Pacific warming slightly, but NO El Niño yet
👉 What is El Niño?
🌊 Warming of Pacific Ocean watersh
🌍 Impacts global weather patterns
👉 When is El Niño Declared?
✔️ Temperature anomaly ≥ +0.5°C
✔️ Must persist for 5 consecutive 3-month periods
🚫 Short-term warming does NOT mean El Niño
👉 Latest Observations
🔵 Feb–Apr: –0.5°C → Weak La Niña influence
🔵 April Monthly anomaly: –0.24°C
➡️ Still below El Niño threshold
👉 What Next?
🟡 Possible development mid–late 2026
🟡 Likely to begin as a weak event
🔴 VAGARIES INSIGHT
👉 No panic, no hype
👉 El Niño is NOT declared yet
👉 It is a slow evolving process
(Forecast uncertainty is often larger at this time of year, due to what is called the "spring predictability barrier". Changes in the climate system in the tropical Pacific during March to May are naturally less predictable than at other times of year. The ensemble forecasts capture some of this additional uncertainty, but may still struggle to accurately forecast through this period.
Models indicate that a moderate El Niño is likely, and many allow for the possibility of a strong event, but it is too early to assign high confidence to those outcomes. We currently have no compelling reason to discount the model guidance, but we should remember that the forecasts are not guaranteed to be reliable.)
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(A) Detailed Meteorological Note:
A Practical Understanding of the El Nino;..to clear misconceptions about the Event.
Various International agencies are monitoring the ENSO conditions. El Nino declaration is
based on the SST anomaly over the regions known as Nino regions and is located over the
equatorial Pacific ocean as shown in the map.
(source: BOM, Australia)
ENSO-neutral conditions are present. Equatorial sea surface temperatures (SSTs) are near-to-above-average in the
central and eastern Pacific Ocean.
ENSO-neutral conditions favored through April-June 2026 (80% chance). In May/July 2026, El Niño is likely to emerge (61% chance) and persist through at least
the end of 2026.
Understanding the El-Nino:
NOAA Operational Definitions for El Niño and La Niña
- As per the (NOAA/CPC/NCEP) Criteria and Definition, To be officially classified as a full-fledged El Niño event, the phenomenon must meet specific criteria regarding sea surface temperatures and duration.
- i.e., Duration: 5 consecutive overlapping 3-month seasons.
- The Chart (Below) shows the Feb/Mar/Apr average as -0.5..indicating La nina conditions at least April end.
- The April Monthly anomaly RONI as -0.24,
- So, the Pre El Nino period shows the El Nino can emerge by September that too initially a weak Event.👇
.{Criteria:
El Niño: Characterized by a positive RONI greater than or equal to +0.5ºC. By historical standards, to be classified as a full-fledged El Niño or La Niña episode, these thresholds must be exceeded for a period of at least 5 consecutive overlapping 3-month seasons *.
- Duration: This anomaly must persist for at
- least 5 consecutive, overlapping 3-month periods.(Refer Chart)}
- Key Criteria for El Niño:Region: Niño 3.4 (5°N-5°S, 170°W-120°W).Measurement: 3-month running mean of higher anomaly.
- Weak: +0.5 to +0.9 anomaly.
- Moderate: +1.0 to +1.4 anomaly.
- Strong: +1.5 to +1.9 anomaly.
- Very Strong: +2.0 anomaly.]
- The Climate Prediction Center (CPC) often looks for consistent atmospheric features (such as reduced trade winds) to accompany the oceanic warming.
