IMD Predicts Above-Normal Rainfall for Mumbai Despite Recent Dry Spell
IMD Predicts Above-Normal Rainfall for Mumbai Despite Recent Dry Spell
18.6.24
In its long-range forecast for the monsoon season, the weather bureau has predicted above-average rainfall for the entire country this year. Consequently, Mumbai is also expected to receive above-normal rains this season, including in June. Although Mumbai typically receives an average of 2,300 mm of rainfall over the four monsoon months, senior IMD scientists anticipate that the city will likely exceed this average.
Following the early onset of the southwest monsoon in the Bay on June 9, the city has been experiencing a dry spell over the past week. Despite nearly 100 mm of rain within the first 24 hours of the monsoon’s arrival, rainfall intensity has significantly decreased, resulting in humid and sultry conditions.
Data from the BMC indicates minimal rainfall from Sunday to Monday morning: the eastern suburbs received 2.90 mm, the Island City recorded 1.28 mm, and the western suburbs saw 0.76 mm.
The India Meteorological Department (IMD) forecasts that Mumbai and its neighboring districts are likely to see a revival of monsoon currents this week. However, as of Monday, the IMD’s Colaba coastal observatory recorded no rain, while the Santacruz station registered only 0.3 mm of drizzle. In the absence of rain, maximum temperatures in both the suburbs and the city are hovering between 33 and 34 degrees Celsius.
Additionally, IMD data indicates that from June 1 to 12, Mumbai city division experienced a 20 percent departure from its long-period average, categorizing it as ‘deficient.’ Meanwhile, the Mumbai suburban district, falling under the ‘normal’ category, registered a 16 percent departure from its long-period average.
According to senior IMD scientists, the southwest monsoon, which entered Kerala on May 30, arrived in Mumbai ahead of schedule due to favorable conditions such as wind interactions and the presence of a shear zone. Although the typical onset date for Mumbai is June 11, this year the monsoon was declared on June 9. However, shortly after its arrival, the shear zone and monsoon currents weakened.
Speaking to The Indian Express, IMD scientist Sushma Nair explained that the westerlies, responsible for bringing rainfall, had also weakened. “The strength of the westerly winds declined in the past week. The presence of westerlies implies moisture, which brings rainfall. Since the westerlies weakened, there was no rainfall,” Nair stated.
Rajesh Kapadia from Vagaries of Weather noted that the usual offshore trough accompanying the monsoon’s arrival in Mumbai is currently absent. “Due to the absence of a strong offshore monsoon trough along the Maharashtra coast, the region is experiencing a lull. Additionally, the monsoon axis trough, typically over central India, is also absent but is expected to develop after June 20-21,” Kapadia explained.
Following a fairly dry week, weather experts predict an uptick in rain activity in Mumbai after June 19. Sunil Kamble, director of IMD Mumbai, told The Indian Express that the rain’s intensity will depend on weather developments over the next few days. Nair added, “Monsoon currents have strengthened considerably, and this week, Mumbai can expect at least moderate showers.”
For Wednesday, the IMD has issued a yellow alert, indicating that heavy rains are likely in certain parts of the district. Although no warnings have been issued beyond that, the city is expected to receive moderate rains throughout the rest of the week.
In a sign of the weather ahead this week, the city experienced cloudy skies on Monday, prompting the IMD to upgrade its forecast to a yellow warning for Mumbai.
