M6.8 solar flare erupts from Active Region 4473
A strong M6.8 solar flare erupted from Active Region 4473 on June 21, 2026, becoming the strongest flare produced by the region so far and the strongest since X1.0 on June 3. The event began at 19:17 UTC, reached maximum intensity at 19:29 UTC, and ended at 19:35 UTC.
M6.8 solar flare on June 21, 2026. Credit: NASA SDO/AIA, The Watchers
The event was associated with a Type Radio II radio emission with an estimated shock speed of 380 km/s, suggesting a coronal mass ejection (CME) was produced.
The eruption originated from Active Region 4473, located in the SE quadrant — not favorable for Earth-directed CMEs. Coronagraph imagery was still unavailable at the time of press, and analysis of the event was in progress.
The same region produced an M1.0 flare at 15:00 UTC on June 20 and an M2.6 flare at 02:46 UTC on June 21.
Radio frequencies were forecast to be most affected over North America and the Pacific Ocean at the time of the flare.
The greater than 2 MeV electron flux remained at normal to moderate levels in 24 hours to 12:30 UTC on June 21, while the greater than 10 MeV proton flux stayed at background levels.
Both are expected to remain unchanged through June 23, with electron flux continuing at normal to moderate levels and proton flux persisting at background levels.
Solar wind parameters returned to background levels during the same period. Total magnetic field strength reached 7 nT, the Bz component varied between +/-5 nT, and solar wind speed held between 350 and 400 km/s. The phi angle was predominantly positive.
Background solar wind conditions are expected to prevail through June 22, followed by enhanced conditions on June 23 due to the expected onset of negative polarity coronal hole high speed stream influence (CH HSS).
The geomagnetic field was quiet during the past 24 hours. Mostly quiet conditions are expected to continue through June 22, with active periods likely on June 23 as the negative polarity CH HSS influence begins.
References:
1 Forecast Discussion – NOAA/SWPC – June 21, 2026
I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in the media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.
Commenting rules and guidelines
We value the thoughts and opinions of our readers and welcome healthy discussions on our website. In order to maintain a respectful and positive community, we ask that all commenters follow these rules.