Just 4 days of Mumbai rains break August record - What's bringing torrential rainfall to city?

Mumbai (AFP)

Mumbai is grappling with severe disruption after being lashed by torrential rainfall for the fourth consecutive day on Tuesday, with the city receiving more rain in a single week than it typically gets for the entire month of August.

According to data cited by The Indian Express, the city has already surpassed its monthly average quota of 566 mm for August. In a staggering comparison, the 791 mm of rain recorded over the past four days nearly equals the 798 mm that fell throughout all of July, which is traditionally the city's wettest month.

The unrelenting downpour has paralysed movement across the metropolis. Train services on the Central line between CSMT and Thane and along the Harbour line were suspended indefinitely due to severe waterlogging. The Brihanmumbai Municipal Corporation (BMC) declared a holiday for all educational institutions and non-essential government offices on Monday and Tuesday.

The impact has been deadly. One person died in a tree-fall incident in Mumbai, while in Nanded, a cloudburst on Monday claimed eight lives. The agricultural sector has also taken a significant hit, with Chief Minister Devendra Fadnavis stating that crops sown over 12 to 14 lakh hectares across Maharashtra have been affected in the past two days.

Rising waters and evacuations 



The intensity of the rain caused the Mithi river to swell alarmingly, its water level rising to 3.90 metres and nearly breaching the danger mark. The Kranti Nagar area in Kurla was inundated with knee-deep water, prompting a major evacuation effort. The BMC, with assistance from the National Disaster Response Force (NDRF), evacuated over 350 people from local slums and moved them to a civic-run school for safety.

A spokesperson for Central Railways explained the widespread travel chaos, stating, “Due to high rise of water level in Mithi river, track water logging level is not being discharged,” as quoted by The Indian Express.

A convergence of weather systems 



Scientists from the India Meteorological Department (IMD) in Mumbai have attributed the extreme weather to a rare confluence of several systems. These include a active monsoon trough, a depression over coastal Odisha, an upper air cyclonic circulation over the north-east Arabian Sea and a shear zone, a narrow band where sharp changes in wind speed trigger cloud formation.

A scientist from IMD Mumbai was cited by The Indian Express as saying that these systems are working in tandem to usher in strong monsoon currents and pull in massive amounts of moisture. They indicated that the rain will only subside after the depression over Odisha weakens.

Record rainfall in suburbs

While the IMD's Santacruz station recorded 223 mm of rain in 24 hours, the BMC’s own automatic weather stations revealed far higher totals in specific suburbs. As reported by The Indian Express, Chincholi Bunder received a drenching 369 mm, followed by Kandivali (337 mm) and Dindoshi (305 mm). Several other areas, including Dadar, Chembur and Vikhroli, recorded rainfall close to 300 mm.

More rain on the horizon 



There is little immediate respite in sight for residents. While the red alert for Mumbai was changed to orange by Wednesday morning, the IMD has forecast heavy to very heavy rainfall to continue until at least Friday.

An orange alert remains in place for Mumbai, Thane and Palghar for Thursday, with a red alert sounded for the neighbouring Raigad district. A yellow alert has been issued for the entire Konkan region for Friday, signalling that the region must brace for further weather-related challenges.