A powerful X1.1-class solar flare erupted from the Sunday on 25 May 2025, triggering temporary radio blackouts across parts of the western Pacific.
Strong X1.1-class solar flare causes outages in Western Pacific
The event was recorded at 01:46 UTC (03:46 SAST) and originated from active region AR4098. Despite initial classifications suggesting this area of the Sun was relatively inactive, it produced not only the X-class flare but also two moderate M-class flares in quick succession.
What is a X1.1-class solar flare?
The term “X1.1-class” refers to one of the strongest types of solar flares.
Solar flares are categorised by strength—A, B, C, M, and X—with X being the most intense.
An X1.1-class flare means it was on the lower end of the X-class scale but still capable of causing high levels of interference to radio and communication systems.
This particular flare caused what experts call an “R3 radio blackout,” which affects high-frequency radio signals and can impact aviation and maritime operations in the affected region.
Solar flares occur when magnetic energy that builds up in the Sun’s atmosphere is suddenly released.
This energy travels through space and can hit Earth’s magnetic field, sometimes disrupting satellite operations and power grids. Fortunately, the recent flare was not accompanied by a coronal mass ejection (CME), a more dangerous phenomenon that sends massive amounts of solar material toward Earth.
Will this affect South Africa?
Although the flare led to disruptions in the western Pacific, including partial outages over oceanic areas, there are no immediate risks reported for South Africa.
According to solar activity reports, only minor M-class flares were linked to low-level blackouts over Africa and the eastern Pacific. The larger X1.1-class flare did not directly impact the southern African region.
South African authorities and space weather services have not issued any warnings related to this solar activity.
At the time of the flare, Earth’s geomagnetic field remained quiet with low disturbance levels, measured on the Kp scale at values between 1 and 2. This indicates minimal geomagnetic activity, making widespread effects unlikely.
Looking ahead, space weather forecasters have noted a 25% chance of more M-class flares and a 5% chance of another X-class event, based on the current conditions of active region AR4098.
While the region is exhibiting unexpected intensity, no Earth-directed CMEs have been observed. Solar wind speeds are also expected to decrease, further reducing the chance of geomagnetic storms.