Mumbai News

After state, monsoon arrives in city – Hindustan Times

Although the city witnessed partly cloudy conditions through the day, the India Meteorological Department (IMD) on Sunday declared the onset of the southwest monsoon over Mumbai and remaining parts of Maharashtra.

The monsoon arrived three days late in Mumbai from its normal onset date of June 11. Last year, the southwest monsoon arrived on June 25 – the most delayed onset in the past 45 years. In 2018, the monsoon arrived on June 9 and on June 12 in 2017.

IMD said the northern limit of the monsoon passes from Surat Gujarat, Nandurbar in north Maharashtra, Betul and Seoni in Madhya Pradesh, and further covering parts of Bihar. “The onset has been declared over Mumbai and remaining parts of Maharashtra on Sunday. Since the onset was within the range of three days of June 11, it will be classified as normal onset for Mumbai and entire Maharashtra,” said Mrutyunjay Mohapatra, director-general, IMD.

Monsoon entered the state on June 11 covering parts of south Konkan, south central Maharashtra and parts of Marathwada. On June 12 and 13, it further progressed covering more areas of central Maharashtra, Marathwada and Vidarbha, and by Sunday, it enveloped the entire state. The onset was declared based on the progression of the monsoon system and factors such as rainfall criteria and monsoon (westerly) winds at middle-troposphere level, said Mohaptra.

“While the criteria is not as stringent as it is for Kerala, basic conditions were met for north Konkan district on Sunday. However, we must realise that onset is declared based on monsoon progression. For example, if Gujarat is witnessing more rain than Maharashtra, we cannot declare monsoon onset for Gujarat before Maharashtra,” he said.

Independent meteorologists had conflicting views on whether conditions were favourable. “The wind pattern and the rainfall criteria have been met, which allowed IMD to declare onset. This time, it was a very soft onset. Usually, people think that onset should be declared only after heavy rain. That’s not the case. Onset criteria could very well be met with light to moderate rains as well,” said Sridhar Balasubramanian, associate professor, IDP Climate Studies, Indian Institute of Technology – Bombay.

Between 8.30am on Saturday and 8.30am on Sunday, the suburbs and south Mumbai recorded 19.7mm and 11.2mm rain, respectively. IMD classifies moderate rain in the range of 7.6mm to 35.5mm. However, moderate to heavy showers were recorded in parts of the Mumbai Metropolitan Region such as Thane, Bhiwandi, Dombivli, Badlapur and Panvel over 24 hours.

Independent meteorologist and PhD researcher at the University of Reading, UK, Akshay Deoras said current conditions were not favourable for declaring the monsoon’s arrival in Mumbai, north Konkan and most of Maharashtra. “These areas continue to witness pre-monsoon thunderstorms. For the state, there needs to be near-surface monsoon winds from the west for declaring monsoon’s arrival. Such wind patterns are currently being observed over south Konkan districts only. Monsoon arrival in north Konkan, including Mumbai, is expected during June 15-16, when all factors are expected to be in place,” Deoras said.

Private weather forecasting agency Skymet had earlier this month set June 13 as the onset date, but later revised it to June 14. Mahesh Palawat, vice-president (meteorology and climate change), Skymet, said, “All conditions for onset were met on Sunday. Now, moderate to heavy rain is expected to pick up from Tuesday onwards till the next weekend.”

IMD had issued a yellow alert for Mumbai, Thane and Palghar for Sunday, but these regions witnessed negligible rain till 8.30pm. An orange alert for heavy to very heavy rain has been predicted for Monday and Tuesday by the weather bureau for Mumbai and surrounding areas.

The first two weeks of June saw the city cover 42% of the monthly rain comprising pre monsoon showers. From June 1 to June 14, Mumbai recorded 208.5mm rain. The average rainfall for the month of June is 493.1 mm.


Sridhar Balasubramanian from Indian Institute of Technology – Bombay said conditions were favourable for heavy rain in the Mumbai region between June 16 and 18. “With the progression of monsoon over whole of Maharashtra, conditions in Arabian Sea are becoming favorable for heavy rain for Mumbai, Thane and Palghar. An existing upper air circulation in the Arabian Sea will strengthen in the coming week between June 16 and June 19. Aided by strong westerlies, we are likely to witness some heavy rain during this period,” he said.

The rain will gradually start increasing from June 15 evening or late night, with heavy rain slated to occur between June 16 evening and June 18 with some spillover rain on June 19. “Overall, we could expect around 200-220 mm of rain in a span of 2-3 days. Heavy rain is likely to occur between June 16 evening to June 18 morning, where an offshore vortex is likely to form near Mumbai. There could be some water logging in low-lying areas during this period,” said Balasubramanian.


According to the India Meteorological Department (IMD), monsoon usually arrives in the city by June 10

· 2020 – June 14

· 2019 – June 25

· 2018 – June 9

· 2017 – June 12

· 2016 – June 20

· 2015 – June 12

· 2014 – June 15

· 2013 – June 9

· 2012 – June 17

· 2011 – June 5

· 2010 – June 11

· 2009 – June 27

(Source: India Meteorological Department)