Mumbai’s only Doppler radar stopped working on Wednesday, a day on which the India Meteorological Department (IMD) had forecast heavy to very heavy rainfall. Repairs to the part of the radar that has stopped working were under way until the time of going to press.
The IMD’s regional meteorological centre has a Doppler radar close to its observatory in Colaba. A radar of this type uses the Doppler effect, or electromagnetic waves, to detect the intensity of surface rainfall and precipitation accumulation among other things.
It helps in nowcasting, which is forecasting weather conditions for a short period of two to four hours.
The IMD uses several tools for forecasting, including weather models and satellite images, and Doppler radars are one of them. The one in Colaba has been functional for about a decade.
The radar stopped working around 4 a.m. on Wednesday. A source at the IMD told The Hindu that a part of the radar had broken down.
“We are repairing the radar, but cannot say right now how long it will take. We have been working since morning and may even work all night. We will restore it soon,” an officer, who did not wish to be named, said.
The radar is imported and serviced by a private company in Bangalore. The agency’s staff in Mumbai has been called in, and the technicians from Bangalore will be called if required. The IMD is trying to restore the radar by Thursday morning.
The Hindu had reported when the radar was briefly closed for maintenance on a rainy day in June last year.
Deputy director general (western region) of IMD K.S. Hosalikar was not available for comment.
Mahesh Palawat, vice president (meteorology and climate change) of private weather forecaster Skymet said, “Using a Doppler radar, you can see the movement of clouds and forecast for next one to two hours. It is crucial for gauging intensity of rainfall and impact area. Cloud images taken by Doppler radar are multi-layered and help with gauging their intensity. In its absence, satellite pictures and wind profile are used to give forecast.”
It will take at least another year for Mumbai to get a second Doppler radar. The IMD has secured land for it in Veravali, Andheri, and is in process of installing it.
Meanwhile, Mumbai recorded 7 mm rainfall between Tuesday and Wednesday morning, while it received heavy rainfall in many parts between 8 a.m. and 6 p.m. on Wednesday. The rainfall till 6 p.m. stood at 21.8 mm. The IMD has forecast heavy rain at isolated places in Mumbai, Thane and Palghar on Thursday.
“On Tuesday, the monsoon current had weakened slightly. But there was rainfall on Wednesday and we are expecting heavy to very heavy falls on Thursday. Rainfall intensity for rest of Maharashtra will decrease next week but Konkan region and ghat areas will continue to see rainfall,” said Bishwambhar Singh, senior scientist at IMD.
