PUNE: In the quiet of IMD’s forecasting division, scientist SD Sanap settled into his chair, eyes fixed on multiple screens displaying weather charts. It’s 9am, and India’s weather story for the day is about to unfold.
“The first thing we do is look at the charts,” Sanap said, gesturing towards displays showing colourful weather patterns. “These surface charts tell us everything __ pressure, temperature, wind direction, wind speed, cloud patterns __ not just for India, but also our neighbouring regions.”
Around him, fellow meteorologists are hunched over their computers, some still plotting data by hand. Despite advanced digital systems, they prefer this traditional approach for its accuracy.
“We still plot some data manually,” Sudeep Kumar, another scientist in IMD’s forecasting division in Pune, said. “Digital systems can have errors, so we cross-check everything by hand. In weather forecasting, every detail matters,” he added.
The room buzzes with increasing activity as more data streams in __ from ocean buoys in the Arabian Sea and Bay of Bengal, from weather stations across the country, and from satellites hovering miles above Earth. Every 15-20 minutes, new satellite imagery refreshes their screens.
“Look here,” Sanap points to a swirling pattern on his monitor. “When we spot a cyclonic circulation, we immediately check if it matches with cloud patterns in the satellite imagery. It’s like putting together pieces of a complex puzzle.”
Sanap also switches between multiple screens displaying colourful weather prediction models. “Models are our window to the future,” he explained, zooming into a detailed simulation. “When we need guidance for the next five days, we turn to these numerical weather prediction models.”
The array of models is impressive __ from IMD’s own Global Forecasting System to specialized global ensemble prediction system. “Think of it as layers of prediction,” Sanap said, pointing to different timeframes on his screen.
“We have short-range forecasts for up to three days, medium-range for up to ten days, and extended predictions that can look ahead for a month, week by week,” he added.
Digital predictions aren’t blindly followed. “Sometimes, a model might underestimate certain weather phenomena,” he said, his eyes scanning the latest data. “As experts, we can modify these predictions based on our experience. The model is a guide, not gospel.”
By 10.30am, the office transforms into a hub of scientific debate. Meteorologists from across India join a video conference, their voices filling the room as they discuss weather patterns and potential forecasts.
“Sometimes, during the monsoon, these discussions can go on until 1pm,” Sanap said. “Every expert brings their perspective, and we often have intense scientific arguments about what the data is telling us.”
The scientists describe how forecasts are tailored for different regions. “Each regional centre takes the finalized inputs and customizes forecasts for their area—like Pune focuses on city forecasts, while Nagpur covers Vidarbha and nearby regions,” Sanap said.
The day doesn’t end with one forecast. As evening approaches, the team reassembles to analyse new data. “Weather never sleeps,” he said, checking fresh observations against morning predictions. “What we saw in the morning might have completely changed by dusk. We have to stay vigilant,” he added.
In the evening, they analyse fresh observations, update the systems’ movements, and refine forecasts if needed. The cycle continues late into the night, ensuring that their predictions are as accurate as possible.
The sun’s signature
The sunshine recorder stands as an elegant meteorological instrument __ a glass sphere on a metal frame with a curved card holder beneath. The sphere focuses sunlight to burn marks on special cards, creating a record of daily sunshine hours.
“The sun’s rays passing through the glass sphere leave burn marks on these cards, like the sun’s signature,” Kripan Ghosh, head of agrimet division, said. The instrument uses different cards seasonally to track the sun’s changing path across the sky.
These recordings are crucial for agriculture. “Sunshine hours directly affect photosynthesis and crop growth. When we measure sunshine duration, we’re measuring the potential for crop development.”
Each dawn, technicians replace the cards, gathering vital data for farmers to make informed decisions.
