150 years of IMD: What the weather agency has planned for the future

The IMD’s overall forecast accuracy has improved by 40% over the last decade, thanks to an overall strengthening of its meteorological observation network across land, sea, and space.

The number of doppler weather radars went up from 15 in 2014 to 39 in 2024, while the number of automatic weather stations increased from 675 to 1,208. The IMD went from having 19 high wind speed recorders in 2014 to 37 in 2024. The number of district-wise rainfall monitoring stations increased from from 3,995 to 6,095. Seven automated weather observing systems and heliport weather observing systems were introduced.

Two geostationary satellites, INSAT 3DR and 3DS, are now monitoring weather round-the-clock, as opposed to the single INSAT 3D in 2014. Crucially, weather model resolution has improved from 25 km to 12 km for medium-range forecasts (with up to 10 days of lead time). A resolution of 12 km means that the IMD now has the ability to forecast events over a 12 km x 12 km area — the better the resolution, the smaller the area for which the IMD can make accurate forecasts.

This improved observational infrastructure has meant that the forecast accuracy across multiple weather forecast windows has increased manifold. Heatwaves can now be predicted with 95% accuracy upto two days in advance, as against 50% accuracy in 2014. Thunderstorms can be detected on an hourly basis with 86% accuracy, as against 50% accuracy in 2017.

The chances of detecting heavy rainfall, upto three days in advance, is 78% today as opposed to only 50% a decade ago. Meanwhile, the accuracy of cyclone track prediction has improved some 35-40% over the past decade, enough to bring down the loss of human lives to zero.

Towards zero-error forecasting

The IMD’s Vision Document 2047 released on Wednesday provides a detailed roadmap for making the country climate smart and weather ready by 2047, the centenary year of India’s independence. The document has chalked out elaborate plans for upgrading the IMD’s capabilities over the next two, five, 10, and 22 years (till 2047).

The agency aims to ensure that at the block level, its forecasts for all severe weather phenomena up to three days in advance are “zero-error” by 2047. For forecasts upto five days in advance, it aims for an accuracy of 90%, and for forecasts with a week’s lead time, it aims for an accuracy of 80%. The IMD aims for an accuracy of 70% of 10-day advance forecasts.

With better monitoring, and issuance of timely warnings, the IMD wants to ensure that the loss of human lives due to any severe weather event is brought to zero over the next two decades. Besides, the IMD will improve the resolution of its weather models from 12 km at present to 5-6 km, which will make it possible to provide hyper-localised weather information at the level of the village panchayat.

Forecasting to management

The IMD is working to introduce critical interventions that will, in the coming decades, take it from merely being a weather forecaster to a weather manager. The department is particularly interested in managing weather phenomena like rain, hail, and fog, which often cause the most havoc.

Mission Mausam, inaugurated by Prime Minister Narendra Modi on Tuesday, provides a roadmap for the IMD to enter the arena of weather modification, and ultimately, management. Among other things, the mission will see the the establishment of a first-of-its-kind cloud chamber at the Indian Institute of Tropical Meteorology (IITM), Pune. This chamber will help IMD scientists to better understand cloud physics, and eventually perfect cloud seeding, a process by which the amount, type, or time of precipitation can be modified through human interventions.

In future, observations could be made using unmanned aerial vehicles, fully-automated weather stations, and sensors based on the Internet of Things which can be placed in the most remote locations in the country. There are plans for climate reference stations at the regional level, and smaller Met centres.

The establishment of mechanisms for having round-the-clock upper atmosphere monitoring at 100 km x 100 km grid using satellites, aircraft-based profilers, radars, and wind profilers are also on the cards.

The IMD will eventually boast 100% detection capabilities for all kinds of weather phenomena. Better data will help improve the performance of the IMD’s weather models, and minimise errors in forecasting.