Minor C7.6 solar flare erupts at 06:54 UTC on October 13, 2025

A minor C7.6 solar flare erupted at 06:54 UTC on October 13, 2025.

Today’s flares include a C6.4 flare from region 4246 (maximum at 00:13 UTC), a C9.3 flare from region 4246 (maximum at 00:36 UTC), a C2.3 flare from region 4248 (maximum at 04:02 UTC), a C5.8 flare from region 4248 (maximum at 04:13 UTC), and an M1.9 flare from region 4246 (maximum at 05:26 UTC).

In 24 hours to 00:30 UTC on October 13, solar activity was at low levels. The strongest flare of the period was a C9.6 flare. The most complex active regions on the visible disk were 4246 and 4248, both of which continued to develop. Other spotted regions remained stable or in decay, and a new region, 4253, was simple and quiet.

Solar activity is likely to remain at low levels, with a chance for R1 – Minor to R2 – Moderate radio blackouts over October 13 to 15, 2025.

Over the past 24 hours, the greater than 2 MeV electron flux reached high levels, and the greater than 10 MeV proton flux remained at background values. The electron flux is expected to remain high for October 13 to 15, with proton flux at background levels during this period.

Solar wind parameters reflected a transition from a corotating interaction region to a high-speed stream. The total magnetic field reached a peak of 16 nT before lowering to between 6 and 8 nT after 09:56 UTC on October 12. The interplanetary magnetic field was primarily northward, but did briefly reach -10 nT. Solar wind speed increased from around 500 km/s to a peak of approximately 750 km/s early in the day. The phi angle was mainly negative.

Solar wind conditions are forecast to remain enhanced for October 13 to 14, 2025, due to ongoing effects from the negative polarity coronal hole high speed stream. A minor enhancement is possible on October 15 from a CME that departed the Sun on October 11.

The geomagnetic field was at active to G1 – Minor geomagnetic storm levels during the past day. Conditions are expected to reach active to G1 – Minor storm levels on October 13, then become unsettled on October 14 as the high speed stream influence decreases. Unsettled conditions are again likely on October 15 due to a passing CME.