Minor C8.7 solar flare erupts at 21:59 UTC on June 28, 2026

A minor C8.7 solar flare erupted at 21:59 UTC on June 28, 2026.

Today’s flares include a C4.1 event from Region 4475 at 01:44 UTC, a C2.4 event from Region 4475 at 06:46 UTC, a C2.2 event from Region 4475 at 07:03 UTC, a C2.7 event from Region 4478 at 15:01 UTC, a C2.8 event from Region 4479 at 20:38 UTC, and a C3.3 event from Region 4477 at 20:50 UTC. Several additional C-class flares of lower magnitude were also observed from Regions 4475 and 4479. There were no reported M-class or X-class flares during this period.

In 24 hours to 12:30 UTC on June 28, solar activity remained at low levels. A long-duration C-class event and a double-peaked C7.4 event occurred, along with several additional minor C-class flares from active regions. No Earth-directed CMEs were detected, and activity was limited to a small set of regions.

Solar activity is expected to remain predominantly low from June 28 to June 30, with the chance for moderate (M-class) flares and a slight chance for major (X-class) flares, especially from Regions 4475, 4478, and 4479.

Active sunspot regions presently observed on the Earth-facing solar disk include AR 4475 (S10W19 – Beta-Gamma), AR 4476 (N08W44 – Alpha), AR 4477 (S15E13 – Beta), AR 4478 (S06E33 – Beta-Gamma-Delta), AR 4479 (N15E16 – Beta), and AR 4480 (S18E07 – Beta).

Over the past 24 hours, the greater than 2 MeV electron flux reached high levels, with a maximum value of 3 792 pfu observed. The greater than 10 MeV proton flux remained at background levels. The electron flux is expected to remain elevated at moderate to high levels over June 28 to June 30, and the proton flux is likely to stay at background levels for the same period.

Solar wind parameters over the past 24 hours reflected a weakening negative polarity coronal hole high speed stream. The magnetic field averaged 2–4 nT, with Bz between ±3 nT, and solar wind speeds decreased from 555 km/s to about 465 km/s. The magnetic field remained mostly in a negative orientation. The solar wind environment is forecast to continue weakening through June 28, with only a slight likelihood that a CME from June 22 may arrive at Earth by the end of June 28. A return to background solar wind conditions is expected for most of June 29, with enhanced activity possible late on June 29 to midday June 30 due to the possible arrival of the June 26 CME.

The geomagnetic field was quiet during the past 24 hours. Periods of active conditions are possible on June 28 if the June 24 CME arrives; otherwise, conditions are expected to remain mostly quiet under the declining influence of the coronal hole high speed stream. Quiet conditions are expected to prevail for most of June 29, with unsettled to active conditions, and isolated G1 – Minor storm periods likely, from late June 29 into early June 30 due to the forecast arrival of the CME from June 26.