Mumbai: Season’s heaviest rain, second-highest 24-hour Sept spell in 26 years
Mumbai’s suburbs witnessed an incessant downpour between Tuesday evening and Wednesday morning with 286.4mm rain, categorised as extremely heavy rainfall.
This is the heaviest rain the suburbs received this season and the second-highest 24-hour September spell in 26 years (1994-2020). This is also the fourth-highest 24-hour September spell recorded during 1974-2020.
A continuous intense downpour on Tuesday night led to water logging in several areas across the Mumbai Metropolitan Region (MMR). After the intensity of rain reduced marginally around midnight, thundershowers were witnessed around 3.30am onwards, followed by intense downpour.
Between 8.30am Tuesday and 8.30am Wednesday, the Santacruz weather station, representative of the suburbs, recorded 286.4mm (extremely heavy) rain while Colaba, representative of south Mumbai, recorded 147.8mm (very heavy) rain. Of this, 107mm rain was recorded over six hours on Tuesday (5.30pm to 11.30pm) and remaining 179.4mm from 11.30pm to 5.30am Wednesday, while south Mumbai recorded 89mm rain over six hours Tuesday (5.30pm to 11.30pm) and the remaining 58.5mm till 8.30am Wednesday. Light rain continued across parts of the city beyond 8.30am Wednesday.
The India Meteorological Department (IMD) classifies 15.6-64.4mm as moderate rain while 64.5-115.5mm rain as heavy, 115.6-204.4mm as very heavy, over 204.5mm as extremely heavy rain, and over 300mm as exceptionally heavy rain.
“Both the suburbs and south Mumbai received very intense rain throughout the night. Most of MMR, especially the entire western side of Mumbai from Colaba to Bhayandar was under thick cloud cover (maximum height 7-8km) causing very heavy rain spells since Tuesday evening. Short bursts of intense rain recorded across isolated areas and the trend continued throughout the night with thundershowers and intense rain spells between 3.30am and 5.30am,” said KS Hosalikar, deputy director general, western region, India Meteorological Department (IMD).
Prior to 24-hour rain between Tuesday and Wednesday, the heaviest rain spell this season for Mumbai suburbs was recorded between August 3 and 4 at 268.6mm. The highest for south Mumbai however was recorded between August 5 and 6 at 331.2mm.
For the 24-hour rain record, on September 20, 2016 Mumbai had recorded 303.7mm rain. Prior to that 312.4mm rain was recorded September 23, 1993 and 318.2mm rain on September 23, 1981.
The weather bureau has predicted a yellow alert (possibility of heavy rain across isolated areas) for the rest of Wednesday followed by a gradual reduction in rain intensity by Wednesday evening.