M5.7 Solar Flare and CME Trigger Atlantic Radio Blackouts
Summary: On May 11, 2026, an M5.7-class solar flare erupted alongside a coronal mass ejection (CME), triggering brief radio blackouts over the Atlantic and raising the probability of visible auroras across the Northern Hemisphere in the coming days.
Event Overview
According to space.com, the event occurred around 13:00 UTC on May 11, 2026. The solar flare registered as M5.7 on the classification scale, placing it in the "medium" category — one tier below the most powerful X-class flares, which are roughly ten times more intense.
The accompanying CME ejected vast amounts of charged particles from the Sun's corona into interplanetary space at velocities of hundreds to over a thousand kilometers per second. When Earth-directed, these CMEs can generate geomagnetic storms upon arrival at Earth.
Impact on Earth
The NOAA Space Weather Prediction Center indicated that the CME could arrive within hours to a day. The flare itself already caused shortwave radio blackouts across the Atlantic region, as the Sun's ultraviolet radiation ionised layers of Earth's ionosphere, disrupting signal propagation.
Upon CME arrival, G1-to-G2 class geomagnetic storms are possible. In past events of comparable magnitude, visible auroras have been observed at mid-latitude locations. More severe storms have been known to accelerate satellite orbital decay, degrade navigation accuracy, and stress power grid infrastructure.
Space Weather Context
The year 2026 falls within Solar Cycle 25's peak phase, characterized by elevated sunspot and flare activity. NASA and NOAA maintain continuous surveillance of active regions on the solar surface, with forecast products disseminated through their respective platforms.
This event aligns with a broader pattern of sustained solar activity throughout early May 2026, during which multiple X-class and M-class flares erupted from active regions and directed CMEs toward Earth.