6-km precision: India’s new weather forecast model races ahead of UK, US and EU in accuracy race

In a bid to sharpen weather predictions down to the village level, the Indian government on May 26 unveiled the Bharat Forecasting System (BFS) — the world’s most precise weather model operating on a 6-km grid.

Union Minister of Earth Sciences Dr. Jitendra Singh inaugurated the world’s first indigenously developed high-resolution weather forecast systems at a launch ceremony held at Vigyan Bhawan today.

Spearheaded by researchers, including Parthasarathy Mukhopadhyay, the breakthrough was enabled by the high-performance supercomputer Arka, installed at the Indian Institute of Tropical Meteorology last year. With a processing speed of 11.77 petaflops, Arka crunches data in four hours, less than half the time taken by its predecessor, Pratyush.

"The previous supercomputer 'Pratyush' used to take up to 10 hours to run the forecasting model. Arka performs the same data-crunching within four hours," Mukhopadhyay told PTI.

At 6 km resolution, BFS becomes the only global numerical weather prediction system in the world at such granularity. In contrast, the global models run by European, British, and US weather agencies operate between 9 km and 14 km resolution.

This new model significantly enhances India’s ability to forecast localised weather patterns. While older systems operated on a 12 km grid, BFS slices that range in half, providing detailed insight into 6x6 km zones — critical for nowcasting and real-time alerts.

Supporting this effort is a network of 40 Doppler Weather Radars across India, which will feed data into the BFS. The radar count is expected to rise to 100, enabling the issuance of hyperlocal nowcasts — forecasts for the next two hours — nationwide.Designed for the tropical belt between 30° South and 30° North, BFS covers the full extent of India, which spans from 8.4°N to 37.6°N latitudes.

The economic stakes are high. The government's Economic Survey pointed to persistent food inflation over the past two years, worsened by frequent extreme weather events. Citing Centre for Science and Environment data, the survey noted that 2024 saw more crop damage than the previous two years due to such events.

The India Meteorological Department recorded a sharp spike in heatwaves — 18% of days between 2022 and 2024, up from 5% in 2020-21. In response, the survey advocates for climate-resilient crops, better price monitoring systems, and reduced post-harvest losses.

Adding to the alarm, the Reserve Bank of India warned in its monthly bulletin about rising temperature anomalies affecting vegetable prices. The RBI emphasised the need for quicker adoption of temperature-resistant crop varieties to help stabilise prices.