Study predicts two extreme solar flares stronger than X14.3 during Solar Cycle 25
A new study predicts that Solar Cycle 25 will produce 2 ±1 extremely strong solar flares (stronger than X14.3) after spring 2027, along with a broader estimate of 5 ±2 flares exceeding X10. The forecast is derived from solar activity data collected since 1975, covering just four complete solar cycles, which introduces a degree of uncertainty.
Representative Image. Image credit: NASA
A new study forecasts that Solar Cycle 25, which began on August 11, 2019, will experience 2 ±1 extremely strong flares (ES-flares) with intensities greater than X14.3, starting around or after spring 2027.
The first ES-flare is expected approximately 7.48 ±0.80 years into the cycle, which corresponds to a window from May 2026 to December 2027. The forecasts are based on statistical analysis of solar activity data collected since 1975, covering four complete solar cycles—introducing a degree of uncertainty.
The study also predicts 5 ±2 strong flares (S-flares), defined as events exceeding X10, during Solar Cycle 25. While less intense than ES-flares, these events remain significant due to their potential to disrupt space- and ground-based technologies. The broader S-flare estimate complements the more narrowly defined ES-flare forecast by covering a wider range of high-intensity solar activity.
The predictions are based on two key metrics from the solar minimum (valley phase) preceding Solar Cycle 25: the mean daily sunspot number (Vₘ = 3.4) and the root mean square deviation of sunspot numbers (V_d = 7.1). Both metrics exhibit strong correlations with the occurrence of powerful flares, with correlation coefficients equal to or exceeding 0.95. Poisson and linear regression models were applied to estimate the number and timing of flares during the cycle.
Researchers propose that powerful flares, especially ES-flares, result from interactions in a low-latitude active zone (LAZ) within ±12° of the solar equator. This zone remains active during solar minimum and enables energy accumulation as sunspots appear closer to the equator during the descending phase. About 65% of ES-flares and 70% of S-flares occur at latitudes below 20°, supporting this model.
Historical data from Solar Cycles 21 to 24 (1975–2024) form the basis for these predictions, with a total of 37 S-flares and 23 ES-flares recorded.
For instance, Solar Cycle 22 produced 14 S-flares and 9 ES-flares, while Solar Cycle 24 was markedly less active, with only 2 S-flares and 1 ES-flare observed. The V_d value of 7.1 for Solar Cycle 25 suggests a moderate level of expected flare activity, placing it between the levels seen in Cycles 23 and 24.
The strongest flare of Solar Cycle 25 is projected to occur around May 2028, approximately 8.78 ±0.93 years after the cycle’s onset. The study also forecasts a total of 108 ±5 X-class flares—defined as flares stronger than X1.0—over the course of the cycle.
As of April 24, 2025, the most intense flare of the current cycle is an X9.0 event on October 3, 2024, which still remains below the S-flare threshold of X10.
The analysis is based on GOES soft X-ray observations and daily sunspot numbers recorded since 1975. Flare intensities were adjusted using a correction factor of 1.43 to ensure consistency across datasets. Parameters for the valley phase were calculated over a 300-day interval centered on the solar minimum. The study acknowledges that the limited sample of four solar cycles introduces uncertainty into the resulting forecasts.
Most S-flares (78.4 %) and ES-flares (82.6 %) occur during the descending phase of solar cycles, when sunspots are generally nearer the equator. This pattern supports the forecast that powerful flares in cycle 25 will cluster after 2027.
References:
1 The Occurrence of Powerful Flares Stronger than X10 Class in Solar Cycles – Baolin Tan, Yin Zhang et al. – The Astrophysical Journal Letters – January 16, 2025 – https://doi.org/10.3847/2041-8213/ada611 – OPEN ACCESS
I’m a science journalist and researcher at The Watchers, contributing to the Epicenter edition, where I cover peer-reviewed scientific research and emerging discoveries across Earth and space sciences. With a background in astronomy and a passion for environmental science, I’ve worked in shark and coral conservation in Fiji, conducting reef and shark-behavior research, contributing to mangrove restoration, and earning PADI Open Water and Coral Reef Certifications. I bring a blend of scientific rigor and storytelling to illuminate the discoveries shaping our planet and beyond.
Now, they are predicting intense activity! Unbelievable! Initially, the selected top panel predicated that this cycle would be very weak, weaker than the previous cycle. But, from the very beginning it was obvious the cycle will break the record number of sunspots. However, Jamal Shrair stated repeatedly that the maximum activity of this cycle will be the strongest ever recorded. But, of course nobody believed him, they believed the experts.