Why India has seen rain, despite projections of an extremely hot summer

The prospects for India were no better. It was expected to be an extremely dry and hot year on the subcontinent. In a sign of things to come, India experienced a heat wave-like situation in February itself, a month for which heat wave conditions are not even defined, since heat waves are expected only in the months of April, May and June. And unsurprisingly, April and May have seen some severe bouts of heatwaves in different parts of the country, also accounting for at least 13 deaths in a tragic incident in Mumbai in April.

There are also monsoon fears, despite IMD’s normal rain forecast. the course development of the child in the equatorial Pacific Ocean, which is expected to become very strong in the coming months, has the potential to spoil India’s monsoon season.

And yet, the first five months of the year have not been very uncomfortable. In fact, far from it. Despite periodic periods of heat waves, both April and May have been surprisingly nice in most of the country.

Average temperatures for the three month period between March and May have been 1 to 4 degrees below normal for most of the country. Only parts of eastern and north-eastern India, and some parts of Gujarat and Maharashtra have seen slightly higher temperatures compared to normal. Average maximum temperatures have remained well below normal in almost the entire country, except for parts of Bihar, Jharkhand, West Bengal and the northeastern states.

Simultaneously, rainfall has been higher than normal during this period. In fact, each of these three months – March, April and May – It has resulted in more rainfall than expected. Over the entire three-month period, India as a whole received 12 percent more rainfall. Central India, comprising Odisha, Madhya Pradesh, Gujarat, GonnaMaharashtra and Chhattisgarh received more than double the expected rainfall during this time.

In fact, it has been the rains that have mainly kept temperatures under control. So much so, that Rajasthan, one of the hottest states in the country, barely had two or three days of heat waves in the entire season. Most of the rainfall activity over the last three months occurred in North and North-West India and Central India, and was caused by western riots.

The IMD data shows that 458 of the country’s 717 districts, about 64 percent, received above-normal rainfall during the three-month period between March and May. Another 104, or about 15 percent, received normal rain. At this time of year, the situation is very similar to 2021, but is otherwise the wettest in the last five years.

Deviation from normal precipitation (in %). (Source: IMD)

Western disturbances are eastward-moving rain-bearing wind systems originating beyond Afghanistan and Iran, picking up moisture from as far away as the Mediterranean Sea, including the Atlantic Ocean. These are examples of extratropical cyclones that are the result of areas of low pressure formed due to interactions between the polar and tropical winds.

Western disturbances frequently influence the climatic conditions of India, particularly in the north-western regions. This year, there were as many as eight riot events in the west in May itself, and a similar number in April, bringing frequent, sometimes heavy rains across much of India.

“There have been a greater number of riots in the west this year. Typically, we expect three to five events in a month,” said IMD scientist RK Jenamani.

In fact, a new western disturbance is expected to cause another spell of rain in northwestern India on Thursday and Friday. South India is also expected to see rain for the next few days due to a different low pressure system. Kerala is likely to receive some rain until Sunday, while some places in Karnataka, Andhra Pradesh and Tamil Nadu could receive rain for the next five days.

However, the current weather conditions in India do not indicate how the rest of the year will unfold. These conditions have been the result of short-term local interactions that do not influence long-term climate.

Monsoon performance will remain critical. Several scientists have been predicting an unusually stronger El Niño this year. While the IMD has said that a positive IOD, a phenomenon similar to the El Niño process but in the Indian Ocean, could offset El Niño’s monsoon impacts to some extent. However, the El Niño effect on the monsoon is known to be much stronger than the Indian Ocean Dipole (IOD).

Monsoon is delayed as of now. On May 31, it was below Sri Lanka in the Indian Ocean, having covered the Andaman and Nicobar Islands the previous week. The IMD said conditions were favorable for the northward monsoon to advance over the next two to three days. The monsoon is usually expected to hit the Kerala coast on June 1, marking the start of the four-month season that brings about 75 percent of India’s annual rainfall. This year, however, IMD has said the start off the coast of Kerala is not likely to happen before June 4.