Minor C8.3 solar flare erupts at 18:14 UTC on May 21, 2026

A minor C8.3 solar flare erupted at 18:14 UTC on May 21, 2026.

Today’s flares include an event at 12:04 UTC on May 21, 2026, with no X- or M-class flares reported in the available event list.

In 24 hours to 12:30 UTC on May 21, solar activity was at very low levels. One region showed some magnetic development, while other numbered regions were stable or in decay.

Solar activity is forecast to remain at low levels through May 23, 2026, with only a slight chance for isolated M-class flares on May 21. Increased activity is anticipated for May 22-23 as multiple active regions rotate into view.

Active sunspot regions presently observed on the Earth-facing solar disk include AR 4436 (N18W78 – Beta), AR 4439 (N06E15 – Alpha), AR 4441 (N07W30 – Beta), and AR 4443 (S16E23 – Alpha).

Over the past 24 hours, the greater than 2 MeV electron flux at geosynchronous orbit remained at high levels, peaking at 1 720 pfu. The greater than 10 MeV proton flux remained at background levels. The electron flux is expected to return to normal to moderate levels on May 21 before rising again May 22-23. Proton flux is expected to remain at background levels through May 23.

Solar wind parameters trended toward background conditions, with speeds decreasing from a peak of 542 km/s to around 430 km/s by the end of the period. The total interplanetary magnetic field reached 6 nT. Mild enhancements are likely on May 21, with more pronounced high-speed stream conditions expected May 22-23 from a positive polarity coronal hole high-speed stream.

The geomagnetic field was at quiet to unsettled levels over the past 24 hours. Isolated active periods are likely on May 21, with quiet to unsettled conditions anticipated for May 22-23 due to continued high-speed stream influences.