C5.5 solar flare erupts on June 17, 2025

A minor C5.5 solar flare erupted at 08:13 UTC on June 17, 2025.

Today’s flares include a C4.1 flare from region 4113 peaking at 00:53 UTC and a C6.8 flare from region 4114 peaking at 01:26 UTC.

In 24 hours to 00:30 UTC on June 17, solar activity remained at high levels with multiple minor to moderate level flares. Notably, a strong M6.3 flare peaked at 09:38 UTC and an M1.8 flare peaked at 04:23 UTC—both from region 4114. Additional activity came from region 4109 with an M1.4 flare at 11:39 UTC, while region 4107 produced C-class flares, including a C6.5 event on June 16 at 01:48 UTC.

The solar activity forecast indicates a 75% chance for moderate flaring and a 30% chance for X-class events from June 17 to 19, primarily driven by the complexity and growth of region 4114.

Over the past 24 hours, the greater than 2 MeV electron flux was at normal to moderate levels, while proton flux stayed at background values. The electron flux is expected to reach moderate to high levels from June 17 to 19 due to continued coronal hole high speed stream influence. Proton flux is forecast to remain at background.

Solar wind conditions showed parameters dominated by coronal hole high speed stream influence, with total field around 8 nT, Bz varying between +/-9 nT, and solar wind speeds in the 470-520 km/s range. This situation is forecast to persist through June 19, with a slight chance for enhanced parameters on June 18 due to a possible interplanetary shock arrival.

The geomagnetic field was at quiet to active levels. Unsettled to active intervals are expected through June 19, with a slight chance for an isolated period of G1 – Minor geomagnetic storming if the anticipated shock arrives.