New Delhi, (Samajweekly) The World Meteorological Organisation (WMO) forecasts on Tuesday indicated a moderate chance (about 65 per cent) of the current La Nina conditions continuing during March-May 2022, and about a 35 per cent chance of their further weakening to El Nino/Southern Oscillation (ENSO)-neutral conditions.
The La Nina that developed in the second half of 2021 remains active in the tropical Pacific, although there are indications of its weakening, in terms of both oceanic and atmospheric parameters, the WMO Global Producing Centres of Long-Range Forecasts said.
La Nina refers to the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in the tropical atmospheric circulation. It usually has the opposite impacts on weather and climate as that of El Nino.
The current La Nina event continues to prevail, with below-average sea surface temperatures (minus 0.5 to minus 1 degrees Celsius) in the central-eastern equatorial Pacific. Atmospheric conditions also remain consistent with a La Nina.
The La Nina event is forecast to dissipate thereafter (after weakening), with ENSO-neutral becoming the most likely category from April-June onward (50-60 per cent chance), according to the latest WMO El Nino/La Nina Update.
The National Meteorological and Hydrological Services (NMHSs) will closely monitor changes in the state of ENSO over the coming months and provide updated outlooks.
El Nino and La Nina are not the only factors that drive global and regional climate patterns, and that the magnitudes of ENSO indicators do not directly correspond to the magnitudes of their effects. “At the regional level, seasonal outlooks need to assess the relative effects of both the ENSO state and other locally relevant climate drivers,” said WMO in a release.
“WMO, now, therefore issues regular Global Seasonal Climate Updates (GSCU), which incorporate influences of all other major climate drivers such as the North Atlantic Oscillation, the Arctic Oscillation, and the Indian Ocean Dipole,” it said.
The Global Seasonal Climate Update is based on forecasts from WMO Global Producing Centres of Long-Range Forecasts and is available to support governments, the United Nations, decision-makers, and stakeholders in climate sensitive sectors to mobilize preparations and protect lives and livelihoods.
