Harsh summer expected as La Niña proceeds to weaken: All you need to know

IMD’s monsoon mission coupled forecasting system has indicated the likely warming of sea surface temperatures over the central and eastern equatorial Pacific Ocean in April and May, which indicates a transition of La Niña to El Niño-Southern Oscillation

The cooling effect of La Niña, a global weather pattern, has started waning and may completely turn neutral in April, the India Meteorological Department (IMD) has said. Here is all you need to know about its impact:

A La Niña year generally receives good rainfall and temperatures are lower than normal. (Representational image/AFP File)

• It is likely to result in harsh summer as La Niña is associated with the cooling of Pacific waters.

• A La Niña year generally receives good rainfall and temperatures are lower than normal.

• La Niña has started weakening after being at its peak in January and February.

• It is often associated with lower temperatures in India.

• But that is now unlikely during the rest of the summer and monsoon months.

• The actual weather conditions will depend on local synoptic features.

• The interaction of westerlies and easterlies over central India is currently causing thunderstorm activity and temperatures have dropped. But overall, La Niña will phase out gradually.

• This means neither El Niño nor La Niña.

• El Niño is a warming of the ocean surface or above-average sea surface temperatures.

• There is also a high probability that La Niña will re-emerge after or during the monsoon, according to IMD.

• The weakening of La Niña conditions indicates a harsh summer is likely.

• There is a 60% probability of ENSO-neutral conditions in April.

• There is no chance of El Niño which makes summer even harsher in India.

• Monsoon is likely to be also normal this year.

• La Niña is expected to re-emerge after the monsoon so it may remain moderate during the upcoming winter.

• ENSO is a periodic fluctuation in sea surface temperatures and the air pressure of the overlying atmosphere across the equatorial Pacific Ocean.

• It has a major influence on weather and climate patterns such as heavy rains, floods, and drought.

• El Niño has a warming influence on global temperatures, while La Niña has the opposite effect.

• In India, El Niño is associated with drought or weak monsoon, while La Niña is associated with strong monsoon and above average rains and colder winters.

• This winter was the third warmest since 1901 when IMD began keeping records.

• It was also the second warmest in the past 120 years when minimum or early morning temperatures were considered. The warmest winter was recorded in 2016 followed by 2009.