Torrential rain ravages Mumbai before IMD's tardy red alert

Most of the damage was done before the IMD upgraded its yellow alert for the day to red at 1 pm. The day ended with the IMD issuing an orange alert for Friday

Mumbai: Heavy rain and gusty winds at 60kmph on Wednesday night and the first half of Thursday left the city in disarray, with waterlogged roads, delayed trains, diverted buses and flights, and uprooted trees.

Mumbai, India. July 25, 2024: Waterlogging on CST road in Kurla area of Mumbai due to heavy rain on Thursday. July 25, 2024. (Photo by Raju Shinde)

Most of the damage was done before the India Meteorological Department (IMD) upgraded its yellow alert – warning only of heavy rainfall in isolated areas – for the day to red at 1 pm. The day ended with the IMD issuing an orange alert for Friday, indicating the likelihood of heavy to very heavy rainfall at a few places.

While the island city was the least affected, the western and eastern suburbs received most of the rain. Between 4 am and 10 am on Thursday, Ghatkopar East and Santacruz had already recorded over 100mm of rain, with many areas receiving in excess of 90mm. With a bulk of the rain having fallen in the dark hours, the day’s average – between 8 am and 7 pm, was 58.54 mm in the island city, 73.79 mm in the western suburbs, and 58.31 mm in the eastern suburbs.

According to the IMD, three weather systems added to the raging rain. “The presence of a shear zone along 22 degrees north, which is tilting southwards with height, along with an offshore trough from south Gujarat to the North Kerala coast and strong westerly winds, all contributed to the heavy rainfall,” said Sushma Nair, a scientist at IMD Mumbai.

As the day progressed, many areas in the city neared the 150mm rainfall mark. From 4 am to 3 pm, the western suburbs received the most rain, with Gundavali recording 161.6mm, followed by three other spots in Santacruz, Kandivali and Dindoshi, which exceeded 150 mm.

In the eastern suburbs, Powai recorded 159.2 mm of rain and Ghatkopar 157 mm. Sewri had accumulated the highest rainfall in the island city, at 112 mm, in the same duration.

The heavy quantum of rain led to complaints of waterlogging in many parts of the city, including Bandra Kurla Complex, Kurla, Chembur, Andheri subway and Veera Desai Road. The Mumbai airport suspended its runway twice during the day, from 8.32 am to 8.42 am and from 10.36 am to 10.55 am. As a result, 10 incoming flights were diverted, while five arriving flights and as many departing flights were cancelled.

A high tide of 4.64 metres at 2.21 pm made matters worse, causing the Mithi river to swell to 2.65 metres at 2.30 pm – approximately a metre below the danger mark, which is 3.5 meters at Kurla. The BMC reported that all 225 pumps were operational to drain water, and all officers were on the ground.

There was chaos in schools as the Brihanmumbai Municipal Corporation (BMC) declared a holiday only at 2 pm, an hour after the red alert was issued. The collectors of Thane, Palghar, and Raigad districts, meanwhile, asked schools to shut during the morning session.

Late Thursday, the BMC announced that all schools and colleges in its jurisdiction will remain open on Friday. “The weather and rainfall in Mumbai are normal at present, allowing life in the metropolitan city to proceed smoothly. As a result, all schools and colleges in the BMC area will remain open on a regular basis tomorrow, Friday, July 26,” the civic body posted on X.

The Maharashtra State Board of Secondary and Higher Secondary Education (MSBSHSE) postponed the class 10 and 12 supplementary board examinations scheduled for Friday, due to heavy rainfall in many districts of the state.

The class 10 exam for Science and Technology Part 2, scheduled for Friday has been postponed to July 31 between 11 am and 1 pm. Class 12 examinations for the three subjects—Organisation of Commerce and Management, Food Science and Technology, and MCVC—scheduled for Friday, have been postponed to August 9 between 11 am and 2 pm.

In the 24 hours ending 8.30 am Thursday, the IMD recorded 68 mm of rain in its Santacruz observatory, the city’s baseline weather station, and 63mm of rain in its Colaba observatory. The BMC’s automatic weather stations were the highest in the eastern suburbs at 90 mm, followed by 89 mm in the western suburbs and 44 mm in the island city.

During the same period, interior parts of the Mumbai Metropolitan Region recorded rains of over 100 mm – Thane (120.4 mm), Ulhasnagar (136 mm), Murbad (228 mm), Bhiwandi (110 mm), and Kalyan (114 mm).