Rainfall

Normal Rains Forecast for India’s SW Monsoon 2022

India Meteorological Department (IMD) has in their first forecast for India’s crucial South West Monsoon (June-Sept) 2022 has forecast[i] that India will receive 99% of Long Period Average (LPA) rain with a model error of +/- 5%. This means that IMD has forecast on April 14, 2022 that India is likely to get normal rainfall (96% to 104% of LPA) rains for the fourth consecutive year. IMD says that currently La Nina conditions are prevailing and are likely to continue during the monsoon.

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Monsoon · Rainfall

Heavy Rainfall in India in Oct-Nov 2021

India has seen rather heavy rainfall in October and November 2021, with October All India Rainfall being 33% above normal and November rainfall being record breaking 86% above normal. The combined Oct + Nov Rainfall was 48% above normal, and by Dec 7, as we write this, it is already 53% above normal for the period from Oct 1 to Dec 7, 2021.

While lingering South West Monsoon brought large part of the excess rainfall in first half of October, the unusually active North East Monsoon with continuous supply of moisture from Bay of Bengal has been the main reason for the high rainfall since late October. The onset of La Nina has also contributed to this and with La Nina forecast to remain in place till March 2022, we are in for continued wet spell in South India, it seems. IMD has already forecast above normal rainfall in South Karnataka during Dec 2021 to Feb 2022.

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Monsoon · Rainfall

SW Monsoon 2021: District wise rainfall in India

In the just concluded South West Monsoon 2021, India received 874.6 mm rainfall, about 99.32% of the Normal SW Monsoon rainfall or just 0.68% less than the normal SW Monsoon rainfall of 880.6 mm as per India Meteorological department. This rainfall will now be categorised as normal rainfall though till the beginning of Sept 2021, the rainfall at national level was 10% below normal. The massive 34.96% surplus rainfall in Sept 2021, thanks to a number of circulations contributed from the Bay of Bengal, ending with Cyclone Gulab and now possibly Cyclone Shaheen has contributed to wipe out the deficit.

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Monsoon · Rainfall

July 2021: High Rainfall days in India’s districts

An analysis of the daily district wise rainfall data from India Meteorological Department (IMD) for the month of July 2021, the 2nd month of India’s South West Monsoon 2021 shows that there were 717 instances when district rainfall of a day was above 50 mm. [Considering that the normal monthly rainfall of India July is 285.3 mm, the average daily rainfall in this month is about 9.2 mm.] Such high rainfall instances included 595 instances when rainfall was 50-100 mm, 98 instances when it was 100-150 mm, 17 times it was 150-200 mm and 7 times above 200 mm. Interestingly, in June 2021[i] too there were seven instances when rainfall was above 200 mm, when the rainfall is supposed to be much below July rainfall. As noted in detailed article[ii], the July 2021 rainfall all over India was 6.7% below normal.

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Monsoon · Rainfall

June 2021: District wise rainfall in India’s SW Monsoon

In the just concluded June 2021, the first month of India’s South West 2021 monsoon, India received 182.9 mm rainfall, 10.96% or about 11% more than the normal June rainfall of 166.9 mm as per India Meteorological department. In June 2020, the rainfall was 196.9 mm, or about 18% above normal and in June 2019 it was 33% below normal.

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Monsoon · Rainfall · River Basin

IMD continues callous reporting of River Wise Rainfall in Monsoon 2020

This rarely gets reported in media, but IMD (India Meteorological Department) also provides river basin wise rainfall figures. Here is an overview of the river basin wise rainfall during SW Monsoon 2020 (June-Sept 2020, though the monsoon withdrew much later), like the way we have been doing for the last three years[i]. Our earlier monsoon 2020 articles provided district wise figures for rainfall in June 2020[ii], June-July 2020[iii], June-Aug 2020[iv] and June Sept 2020[v].

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Monsoon

Surplus 2019 monsoon in India proves IMD and Skymet Wrong

Though South West Monsoon has not even started withdrawing from India, the IMD (India Meteorological Department) Press Release on Sept 30, 2019[i] has rather bureaucratically declared: “The 2019 southwest monsoon season comes to end with above normal seasonal (June to September) rainfall.” Why should the monsoon shop be closed even as the monsoon has refused to start withdrawing? May be the IMD was not happy that the SW Monsoon 2019 proved it so wrong, again!

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DRP News Bulletin

DRP News Bulletin May 7, 2018: WESTERN GHATS FORESTS ARE VITAL FOR SOUTH WEST MONSOON RAINS IN TAMIL NADU

W Ghats Forests vital for Tamil Nadu SW Monsoon Rains Researchers have found that the dense vegetation in the Western Ghats determines the amount of rainfall that Tamil Nadu gets during the summer monsoon. A team led by Prof. Subimal Ghosh from the Department of Civil Engineering at the Indian Institute of Technology (IIT) Bombay has found that dense forests of the Western Ghats contribute as much as 40% of moisture to the southwest monsoon rainfall over Tamil Nadu during normal monsoon years. The average contribution is 25-30%. But during monsoon deficit years, the contribution increases to as high as 50%. Continue reading “DRP News Bulletin May 7, 2018: WESTERN GHATS FORESTS ARE VITAL FOR SOUTH WEST MONSOON RAINS IN TAMIL NADU”