How IMD's response to extreme weather events improved in last few years

Not long ago, in 2015, the Bombay High Court sought a reply from the India Meteorological Department on whether a separate Met subdivision could be created for Mumbai and the weather forecast be provided every four hours as against every 24 hours.

A Division Bench of Chief Justice Mohit Shah and Justice Anil Menon was hearing a PIL (public interest litigation) petition by advocate Atal Dubey after Mumbai came to a standstill following floods so heavy that the loss of life and property could not be assessed with accuracy. The court said, “(The) IMD states that the same system used in 2006 continues today. We direct the IMD to consider issuing weather forecast every four hours during monsoons from June to September.”

The court also said there was lack of coordination between the IMD and other authorities.

“The commission refers to the role of the disaster management agency. Since the chairman of the disaster management cell in Mumbai is municipal commissioner, we have directed him to submit a report indicating if recommendations of the commission have been accepted and implemented by the Brihanmumbai Municipal Corporation (BMC),” added the Bench.

 

The court’s order in some ways hit the nail on the head. The Met’s errors, compounded by lack of coordination between agencies, did little to mitigate the effects of a weather event. Even if there was an accurate forecast, if it led to an extensive loss of life because preparations on the ground were inadequate to meet the ferocity of the elements, the forecast was by and large irrelevant.

But judging by the accuracy of the IMD’s forecasting of recent cyclones Amphan and Nisarga on the East and West coast of India and coordination with the National Disaster Management Agency (NDMA), it would seem that the days of wobbly and unreliable forecasts and loss of lives from weather-related disasters may be a thing of the past.

How has this happened? What is that the IMD is doing differently in the last few years that it was not able to do earlier?

As the director general of the IMD, Mrutyunjay Mohapatra, puts it, just as a doctor relies on accurate pathological and clinical tests to come up with the prognosis of a disease, a meteorologist too has to depend on forecasting models that are fed with different weather observation to arrive at a near-accurate forecast for a region.

India’s observatory data collection has gone up several notches in the last few years, which helps in making accurate prediction, something that wasn’t the case a few years ago.

The 20 weather buoys and advanced weather ships that collect data from the depths of the ocean, alongside 26 Doppler radars that monitor the climatic condition in the land, give the Met foolproof data on sea surface temperature, wind speed, high- and low-pressure systems, etc all of which are used to generate accurate predictions of severe weather events such cyclones, floods, thunderstorm, and lightening.

The launch of two high-powered advanced weather satellites, INSAT-3D and INSAT 3D-R, by the Indian Space Research Organisation (Isro), in 2013 and 2016, has added on to the IMD’s observation data collection capabilities.

“All these direct and remote sensing observations are helping the forecaster get a better assessment of the current weather systems 24X7 through which one can detect high pressure and low pressure systems, its characteristics, evolution, etc,” Mohapatra said.

While the data from the various observatories gets collected it is simultaneously digitised, processed, and fed into almost seven numerical weather prediction models (developed by the Ministry of Earth Sciences) that recreate the atmosphere in laboratories. The numerical weather prediction models are nothing but a set of mathematical equations that aim to create atmosphere in the labs based on the inputs fed into them.

The Met now has the capability to forecast severe weather events for every 3 km.

The IMD’s computing power to process observational data has vastly improved due to increase in its computing power to 8.6 teraflops from one teraflops earlier. Faster computing can give output within three hours after observational data is fed into the numerical prediction models. Earlier this would take 12-14 hours.

The IMD, along with its sister concerns under the Ministry of Earth Sciences, plans to narrow global forecasting to a 5-km range from the current 12 km and add 28 Doppler radars to the existing 26 so that localised weather events such as thunderstorms and lightening can be accurately predicted.

It also has plans to further streamline the three-tier coordination mechanism with the National Disaster Management Agency, the National Disaster Response Force (NDRF), and the Ministry of Home Affairs at the national level, the state emergency operations centre and district disaster management officials to minimise the loss of life and property.

“The formation of the NDRF, along with state disaster response teams such as the Odisha Disaster Rapid Action Force and also such specialised force in other states, is a big help because without rapid response, early warning of extreme weather event is useless,” Mohapatra added.