IMD issues ‘yellow’ alert for the city till Monday

Indian Meteorological Department (IMD) issues a 'yellow' alert for Mumbai due to heavy rain and thunderstorms expected to peak over the weekend. Thane and Palghar are also on 'yellow' alert. The IMD's doppler radar, used for forecasting, has been dysfunctional since September 9.

Mumbai: In impending news of heavy rains returning to the city with full force, the Indian Meteorological Department (IMD) has issued a ‘yellow’ alert for the city starting Thursday till Monday. The intensity of rain will gradually increase and is expected to peak over the weekend, bringing heavy rains, thunderstorms, and lightning at isolated places.

HT Image

Thane and Palghar are also on ‘yellow’ alert till Monday except for Sunday, when it is on ‘orange’ alert.

The observatory in Santacruz recorded 34.3mm of rain, while the one in Colaba recorded only traces between 8:30am and 5:30pm on Thursday. According to the BMC’s press release, however, the city saw 6.31mm, the eastern suburbs saw 18.87mm and the western suburbs 8.74mm between 8am and 6pm.

“There’s a well-marked low-pressure system right now over the coast of Odisha. It’s likely to move inside over Chhattisgarh and Madhya Pradesh in the next two days,” said Sushma Nair, scientist at IMD Mumbai, explaining the system behind the showers. “It’s going to be a wet weekend.”

“On Friday, rains over Mumbai will be light to moderate,” said Mahesh Palawat, vice president at Skymet Weather. “Thereafter the intensity will gradually increase, peaking on September 18 and 19, the rains lasting till at least September 20. Then it will gradually decrease.” That, however, will not mean the end of the monsoon over the city.

Amidst this expected heavy rain, a key piece of the IMD’s forecasting system, the doppler radar has been dysfunctional since last Saturday, September 9. Athreya Shetty, an independent meteorologist, said, “We’ve been unable to track where the showers are coming from, and which areas are affected. If it continues not to work over the weekend when the heavy spell is expected, it may be a big issue.”

He explained the doppler helps in nowcasts, a more immediate forecast for the next hours, and on a micro-local scale. “It’s useful to see when exactly the rains will start, if cloud bands are forming and when will they move in.”

The radar is being repaired by the IMD’s engineers, informed Sunil Kamble, head of the Regional Meteorological Centre, Mumbai, although he could not assure of when it would be up and running in case replacement of parts is needed. “We use other satellites and other numerical models for our forecasting. The radar is only one of the tools at our disposal, so there should not be much of an issue.”