Mumbai may get heavy rain today, says IMD

Incessant downpour over the weekend led to the second highest 24-hour July rain over the past five years in the city.

Incessant downpour over the weekend led to the second highest 24-hour July rain over the past five years in the city.

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After three days of heavy to very heavy rain, the India Meteorological Department (IMD) revised its forecast for Monday by issuing a yellow alert for all Konkan districts, including Mumbai, and predicted the possibility of heavy rain across isolated areas. Earlier, the weather bureau had not issued any warning for Monday.

“Models have indicated moderate rain with intermittent heavy rain to continue on Monday but the intensity of rain is likely to be lesser than Friday to Sunday,” said KS Hosalikar, deputy director general, western region, IMD.

Between 8.30am on Saturday and 8.30am on Sunday, the Santacruz weather observatory, representative of the suburbs and Mumbai, recorded 200.8mm rain, falling under the ‘very heavy’ category.

Last year, the city had recorded 375.2mm rain on July 2, which is the highest 24-hour July rain since 2015. In 2018, it was 184.3mm on July 10, 163.4mm in 2017 on July 18, 114.5mm in 2016 on July 30, and 61mm in 2015 on July 21.

Over the past decade, however, more rain was recorded in 2013 (215.6mm on July 24) and 2014 (207.2mm on July 3). The all-time high 24-hour July rain was recorded on July 27, 2005 that led to 944.2mm.

Colaba weather station, representative of south Mumbai, recorded 129.6mm rain between 8.30am Saturday and 8.30am Sunday.

On Sunday, the suburbs woke up to intense heavy rain with 95.4mm over a span of 3-hours (8.30am to 11.30am) that later increased to 103.9mm over 12 hours (8.30am to 8.30pm). South Mumbai recorded intermittent light showers of 11.2mm during the same time. Majority of Sunday’s rain was concentrated towards parts of the suburbs, central Mumbai, and outskirts of the city. Thane recorded 179.4mm rain.

Over the past 60 hours (8.30am Friday to 8.30pm Sunday), Mumbai suburbs recorded 461.7mm rain while south Mumbai recorded 309.2mm rain.

Thane recorded the highest rain across the Konkan region and the state over 24-hours at 377mm, which falls under the exceptionally heavy category.

IMD classifies 15.6-64.4 mm as moderate rain while 64.5-115.5 mm rain as heavy, 115.6-204.4 mm as very heavy, and over 204.5 mm as extremely heavy rain.

“North Konkan, including Mumbai, witnessed an active phase of the southwest monsoon over the past three days with continuous showers and extremely heavy rain in some areas. The impact of widespread rain activity led to overall excess rainfall for majority of the weather stations,” Hosalikar.

Mumbai suburbs currently recorded 15% excess rain for the season while south Mumbai has recorded excess of 29%.

The city has so far recorded 489mm rain (from July 1 to July 5, 8.30pm), which is 58% of the month’s average rainfall (840.7mm). The city had recorded 395mm rain in June, which was the lowest monthly rain in five years. However, with continuous downpour, the city has so far (from June 1 to July 5, 8.30pm) received almost 38% of its seasonal average rain (883.5mm of 2,317mm).

Independent meteorologists said weather systems responsible for heavy rain over Mumbai were expected to move northwards towards south Gujarat leading to decline in rain intensity for the city.

“Massive cloud bands in the Arabian Sea, as a result of the offshore trough, along with strong westerly winds led to these rains over three days. Now, there are chances of intermittent moderate showers for Mumbai on Monday while major rain intensity will be felt in Gujarat coast owing to a low-pressure system in Arabian Sea located close to Gujarat,” said Professor Sridhar Balasubramanian, department of Mechanical Engineering and IDP Climate Studies, Indian Institute of Technology-Bombay.