Mumbai and Thane districts have been placed under a yellow alert by the India Meteorological Department (IMD) as the region anticipates continued rainfall. The alert signifies a possibility of heavy downpours in isolated pockets, alongside gusty winds that could reach speeds of 40-50 kmph. This forecast extends for Monday, with moderate rainfall expected to persist over the next three days.
The region has been experiencing intermittent spells of light to moderate rain throughout the weekend. Between Saturday and Sunday morning, the Colaba observatory recorded 20 mm of rain, while the Santacruz observatory registered 7.2 mm. Neighbouring Thane recorded 23 mm during the same period. In Navi Mumbai, rainfall varied across different nodes, with Belapur receiving 37 mm, Koparkhairne 36 mm, and Nerul 31.4 mm.
Forecast Details and Weather Systems
Meteorologists attribute the current spell of rainfall to a shear zone, which includes a low-pressure system situated over the western coast of India. This system is drawing moisture from the Arabian Sea, leading to an increase in rainfall activity across the Konkan belt and Gujarat. The intensity of the rain is forecast to gradually decrease after Tuesday. For the period starting Tuesday, the IMD has predicted only moderate rain for Mumbai, Thane, and Palghar.
However, specific areas within Raigad district, including Navi Mumbai, may experience heavy to very heavy rainfall, prompting an orange alert for the district. This pattern suggests a localized intensification of monsoon activity.
Water Stock and Reservoir Levels
The ongoing rainfall has had a positive impact on the water stock for Mumbai. Data from the Brihanmumbai Municipal Corporation (BMC) indicates that the water stock in the city’s seven lakes has reached 61.90% of their total capacity, an increase of 4.15 percentage points in a single day. Tansa Lake became the second reservoir this year to reach its full capacity, following Tulsi Lake earlier in the month. The current water stock is estimated to be sufficient for approximately 375 days, at the current supply rate of 3,850 million litres per day (MLD) against a demand of 4,200 MLD.
Past Rainfall and Advisories
In the past 24 hours, rainfall in the catchment areas of Mumbai’s water sources ranged between 65 mm and 224 mm, with the Upper Vaitarna receiving the highest precipitation. This contrasts with the previous year, when water stock stood at 85.32% on July 22, compared to 47.29% in 2024. For context, the seven lakes supplying potable water to Mumbai are Tulsi, Vihar, Bhatsa, Tansa, Upper Vaitarna, Middle Vaitarna, and Modak Sagar. Tulsi and Vihar lakes are located within the city limits, while the others are situated in Thane, Palghar, and Nashik districts.
Authorities are advising residents to exercise caution, particularly during periods of heavy downpour and strong winds. There have been instances of uprooted trees and fallen branches across the city due to the adverse weather conditions. Travel advisories are in place, with commuters urged to stay updated on weather forecasts and civic advisories.
The Chenab Times News Desk