E-Paper
Monsoon season comes to an end, departure likely to be in October
IMD predicted on May 27 that the monsoon is likely to see rainfall of 106% of the long period average with a model error of ± 4%
The 2024 monsoon season officially came to an end on Monday with around 8% excess rainfall, although, continuing the trend seen in recent years, its departure is likely to be delayed well into October.
And while the India Meteorological Department has maintained that its arrival is always on schedule, at the beginning of June, that month is increasingly becoming drier. This year, for instance, June ended with a deficit of 10.9% compared to the long period average (the average between 1971 and 2020). In contrast, July, August and September were wetter, with 9%, 15.3% and 12.5% excess rain.
Much like recent years, there is also a wide regional disparity in rains this monsoon season: east and northeast India recorded a deficiency of 14%; northwest India, an excess of 7%; central India, an excess of 20%; and peninsular India, an excess of 14% .
IMD predicted on May 27 that the monsoon is likely to see rainfall of 106% of the long period average (LPA) with a model error of ± 4%. LPA for the season as a whole is 87 cm. Last year, the monsoon was “below normal” with rainfall at 94.4% of LPA. The 2022 monsoon was “above normal” with rainfall at 106% of LPA and the 2021 one, a “normal” monsoon, with rainfall at 99% of LPA .
But while the season is officially over, rains are continuing in many parts of India. Heavy rain and flooding are continuing in parts of the country especially Bihar. Heavy to very heavy (6.5 cm to 20 cm) rainfall is likely over northeastern states over the rest of the week according to IMD.
Interestingly, India recorded an above average monsoon and several events of extreme unprecedented rainfall despite La Nina not developing as expected during the monsoon although it may emerge now.The Climate Prediction Center of the US National Oceanic and Atmospheric Administration said on September 12 that La Niña is favored to emerge in September-November (71% chance) and is expected to persist through January-March 2025.
La Nina refers to the periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific that occurs every three to five years. In India, it is associated with strong monsoon and above average rains and colder winters.
“This year was above normal monsoon year as expected by IMD in their seasonal forecast. The above normal rainfall was in spite of La Niña and positive Indian Ocean Dipole not developing as we expected. On mutlidecadal time scale we are in positive mode. We may expect more rainfall in coming years,” M Rajeevan, former secretary, ministry of earth sciences and climate scientist said.
“We should expect more rainfall extremes and floods in the coming years. Our early warning systems should improve substantially. This year we could predict some events but we missed some events. MoES (the ministry of earth sciences) with the new Mausam mission should focus in improving predicting extreme events because it has a huge impact on our economy,” he added.
IMD said on Monday that conditions are becoming favourable for the further withdrawal of the monsoon from some more parts of Rajasthan, Haryana, Punjab and some parts of Jammu-Kashmir-Ladakh-GilgitBaltistan-Muzaffarabad and Himachal Pradesh over the next two to three days.
HT reported on June 25 that India’s summer monsoon is undergoing significant changes, influencing not just agriculture – for which the rains are a lifeblood --- but also the length and intensity of the summer.
Recent data from t IMD shows a trend of weaker monsoon rainfall in June, followed by prolonged, heavy rainfall in September. This shift is accompanied by rising temperatures during monsoon months and an increase in the number of dry days over eastern India. This trend was quite clear this year.
Since 2008, nine years have seen a below normal monsoon rainfall in June and six recorded near normal to above normal rainfall, as per data with IMD.
