El Nino is likely to establish by June 2023. With this comes increased chances of hotter-than-normal temperatures globally. There is still a bit of obscurity on the exact time of commencement, intensity and duration. Notwithstanding, a moderate or even mild El Nino could affect precipitation and temperature patterns significantly.
ENSO: Negative sea surface temperature anomalies have weakened across most of the equatorial Pacific Ocean. During the last 4 weeks, positive SST anomalies persisted in the central and eastern Pacific with large amplitude near the coast of Peru. All the Nino indices have been warming consistently. Nino 3 and Nino 1+2 have breached the threshold mark of +0.5 degrees. The other two, Nino 4 and Nino 3.4 are just short by a whisker, both placed at +0.4 degrees.
El Nino conditions are likely to manifest by June 2023. Warming is expected to accelerate thereafter. Following this, an El Nino event may be declared.
IOD: Indian Ocean Dipole is currently neutral. The IOD index for the week ending 30 April 2023 was +0.04 degrees and the same value a week prior also on 23 Apr 2023. Model projections through the monsoon months indicate a fair amount of fluctuations. The sharp rise in temperature during the first half of the monsoon is getting neutralized in the 2nd half. The pattern needs to be observed with caution as the model accuracy is very low at this time of the year.
MJO: Madden Julian Oscillation is now placed on the borderline of the Indian Ocean and Maritime Continent. Quick propagation is likely from the Maritime Continent in Phase 5 to Western Pacific in Phase 6. Amplitude, which had earlier taken a dip is likely to strengthen. A tropical cyclone developing over the Bay of Bengal may not be influenced directly by MJO, but its positioning over the Pacific will at least not suppress the fortification of potential storm Mocha.
ENSO is a naturally occurring phenomenon. However, human-induced climate change is expected to impact the behaviour and dynamics of El Nino events. Under the warmer envelope of the ocean and lower atmosphere, these events may become 'extreme' in future. El Nino may bring increased rainfall over southern South America and the Horn of Africa. It may inflict damaging drought in Australia, Indonesia and parts of Southern Asia, including India.
