University of Warwick Researchers Find Way to Predict Solar Storms Years Ahead

The Sudden End of Extreme Space Weather

For centuries, tracking the Sun has felt like watching a flickering bulb with no predictable switch. Astronomers have long known that the Sun moves through an approximately 11-year cycle marked by the reversal of its magnetic poles and the rise and fall of dark, magnetic sunspots. These regions drive solar flares and coronal mass ejection events that can disrupt satellites, communication networks, and power grids on Earth. Yet forecasting how intense any given cycle will be has remained notoriously difficult because no two cycles behave alike.

Now, researchers propose a new way to read those patterns. Scientists from the University of Warwick announced that the most intense solar activity does not simply fade away as a cycle winds down. Instead, it stops abruptly.

Sandra Chapman, Professor of Physics and Director of the Centre for Fusion, Space and Astrophysics at the University of Warwick, explained that the Sun does not gently go to sleep and then gently wake up again, adding that researchers have discovered that the most extreme space weather switches off quite suddenly at a specific point in every solar cycle and that by identifying that point, they have found a new way to predict how active the next solar cycle is likely to be.

This discovery was presented at the Royal Astronomical Society’s National Astronomy Meeting in Birmingham, building on a conceptual framework the team introduced in 2020 known as the sun clock, which maps the Sun’s irregular rhythms onto a standardized timeline.

How the Switch-Off Point Predicts Solar Cycle 26

The forecasting technique centers on counting the sunspots visible when the Sun hits this newly defined threshold. Researchers discovered a direct correlation between the number of sunspots present at the switch-off point and the peak sunspot count of the subsequent cycle.

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Traditional forecasting methods require scientists to wait until the solar minimum—the quietest phase between cycles—before making stronger predictions. By identifying the switch-off point instead, researchers can gauge the intensity of an upcoming cycle roughly six to seven years before it reaches its maximum.

Using this approach, the team has already produced an early estimate for Solar Cycle 26. Initial projections point to a moderate cycle with a sunspot number between 100 and 120, placing it at a level comparable to or slightly weaker than the current Solar Cycle 25.

Real-World Testing Against Solar Cycle 25 Storms

The forecasting model earned attention after successfully anticipating that Solar Cycle 25 would prove more active than many competing forecasts suggested.

Despite these successes, researchers emphasize that the forecast for Cycle 26 remains preliminary.

Sandra Chapman, Professor of Physics and Director of the Centre for Fusion, Space and Astrophysics at the University of Warwick, stated that they are about two years away from the switch-off point for the current Solar Cycle 25, noting that at the moment they have to estimate where that point will be, but once they reach it they can use observations alone to make a much more precise prediction for Solar Cycle 26, which will still give them around seven years’ warning of how strong the cycle is likely to be.

By relying on direct empirical observations rather than projections once Cycle 25 hits its switch-off threshold, scientists hope to refine their models and gain deeper insight into the solar dynamo—the complex physical process that generates and maintains the Sun’s magnetic field.