Strongest Solar Flare of 2025 (X5.1) Triggers Radio Blackouts; NOAA Confirms G4 Geomagnetic Storm
Sunspot AR4274’s powerful eruption at 10:04 UTC on Nov. 11 caused R3 radio blackouts across parts of Africa and Europe. A fast coronal mass ejection then drove “Severe” G4 geomagnetic storm levels early Nov. 12, with additional disturbances possible through Nov. 13, forecasters say. Space+2Space Weather+2 Updated: Nov. 12, 2025 The sun unleashed an X5.1‑class solar flare on Tuesday, Nov. 11, the most powerful flare of 2025 so far and the strongest since October 2024, according to astronomers. The eruption from active region AR4274 peaked at 10:04 UTC and immediately caused R3 (Strong) high‑frequency radio blackouts on the dayside of