Minor C9.8 solar flare erupts at 22:33 UTC on December 27, 2025

A minor C9.8 solar flare erupted at 22:33 UTC on December 27, 2025.

Today’s flares include an M5.1 event peaking at 01:50 UTC from region 4325 and several low-level C-class flares, including C4.8 at 00:32 UTC (region 4324), C3.7 at 05:39 UTC (region 4324), C4.5 at 07:58 UTC (region 4317), and multiple additional C-class events from regions 4321, 4324, and 4325. No X-class flares were observed.

In 24 hours to 12:30 UTC on December 27, solar activity reached high levels due to an M5.1 flare. Regions 4317 and 4324 contributed low-level C-class activity. No Earth-directed CMEs were detected.

Solar activity is expected to be low with a chance for M-class flares through December 29.

Active sunspot regions presently observed on the Earth-facing solar disk include AR 4312 (N19W48 – Alpha), AR 4316 (S08W45 – Alpha), AR 4317 (N11W06 – Beta), AR 4319 (S10E15 – Beta), AR 4320 (N05E27 – Alpha), AR 4321 (S10W36 – Beta-Delta), AR 4322 (N13W77 – Beta), AR 4323 (S12E61 – Alpha), and AR 4324 (N28E75 – Beta).

Over the past 24 hours, the greater than 2 MeV electron flux reached high levels with a peak of 8 194 pfu at 16:55 UTC on December 26. The greater than 10 MeV proton flux remained at background levels. Electron flux is expected to remain high on December 27 and 28, returning to normal to moderate levels by December 29. Proton flux is expected to stay at background throughout.

In the past 24 hours, solar wind parameters gradually decreased as coronal hole high speed stream effects weakened. Wind speed dropped from approximately 550 km/s to 500 km/s, the total magnetic field averaged near 6 nT, and the Bz component varied between +/-5 nT. The phi angle remained predominantly positive. Solar wind parameters are expected to trend toward background levels from December 27 to 29.

During the past day, the geomagnetic field was at quiet to unsettled conditions. Mostly quiet geomagnetic levels are expected from December 27 to 29, with isolated unsettled periods possible as coronal hole influences weaken.