Several parts of Mumbai continued to receive light to moderate rain on Friday, when the India Meteorological Department`s (IMD) 24-hour forecast issued a green alert for the city, indicating light rainfall or thundershowers. Meanwhile, the nowcast on Tuesday afternoon and evening — issued every three hours — showed a yellow alert for Mumbai, indicating moderate rainfall.
In a statement on Friday evening, the Brihanmumbai Municipal Corporation (BMC) said, “Light to moderate spells of rain are very likely with a possibility of thunder and lightning accompanied by occasional gusty winds reaching 40-50 kmph in some areas in Mumbai, Palghar, Raigad, and Thane.”
Thundershowers indicate short, intense spells of rain, as witnessed on Sunday. This is contrary to rainfall during the monsoon season, which can continue throughout the day. In the 24 hours between Thursday and Friday, Mumbai`s Colaba weather station recorded 4 mm of rainfall, while Santacruz witnessed 7 mm.
Why still raining?
The IMD has said this is unseasonal rainfall. It announced the withdrawal of the southwest monsoon from Mumbai on October 10. Over the last weekend, however, the IMD had predicted rain for Mumbai and coastal Maharashtra till Thursday (October 30), with thundershowers in isolated places. According to IMD`s forecast, Mumbai is on green alert with light rainfall throughout this weekend. Coastal districts of Maharashtra, including Thane, Palghar, and Raigad, are on yellow alert (moderate rainfall).
Better air quality
The unseasonal rainfall has improved Mumbai`s air quality slightly, in comparison to last week during the festive season of Diwali. According to the Central Pollution Control Board (CPCB), Mumbai recorded an air quality reading of 150-160, as against 171 during Diwali. However, various CPCB monitoring stations recorded air quality in the ‘poor’ and ‘very poor’ categories, with BKC recording an Air Quality Index (AQI) of 301 (very poor) and Deonar recording 207 (poor).
According to Swiss air quality technology company IQAir, Mumbai has moved down to 37th position, a major improvement from its earlier 6th and then 3rd position among the world’s most polluted cities. IQA records air quality for 126 cities across the world.
