Moderate M1.3 solar flare erupts at 16:32 UTC on October 17, 2025

A moderate M1.3 solar flare erupted at 16:32 UTC on October 17, 2025.

Today’s flares include an M1.5 event from region 4246 (01:28 UTC), an M1.1 event from region 4246 (12:45 UTC), and an M1.0 event from region 4246 (14:32 UTC), along with several C-class flares. No specific M1.3 flare is listed by time in the provided event summary, but multiple M-class events from region 4246 are confirmed.

In 24 hours to 12:30 UTC on October 17, solar activity remained at moderate levels with several M-class flares and numerous C-class flares recorded. Activity was primarily associated with region 4246, while other regions were less active.

Minor to moderate R1-R2 radio blackouts are likely through October 18, with a slight chance for an isolated R3 event. Probabilities decrease slightly on October 19 as region 4246 rotates off the visible disk.

Active sunspot regions presently observed on the Earth-facing solar disk include AR 4246 (N24W69 – Beta-Gamma-Delta), AR 4248 (N07W41 – Beta-Gamma), AR 4250 (N05W34 – Alpha), AR 4252 (S13E14 – Beta), AR 4254 (N10E46 – Alpha), AR 4255 (S08E38 – Beta), and AR 4256 (S16E66 – Beta).

Over the past 24 hours, the greater than 2 MeV electron flux reached high levels, with a maximum flux of 3 769 pfu observed. Greater than 10 MeV proton flux remained at background levels. The electron flux is expected to decrease to normal to moderate levels on October 17 due to glancing CME effects, then return to high levels on October 18–19. There is a slight chance for an S1 – Minor solar radiation storm through October 18.

Over the past 24 hours, solar wind parameters were nominal until 09:30 UTC when a CME-induced enhancement increased the total field to 12 nT and Bz southward to -9 nT. Solar wind speeds remained near 380 km/s. Further enhancements are anticipated through October 18 from glancing CME effects, with conditions expected to return to nominal on October 19.

Over the past 24 hours, geomagnetic field activity ranged from quiet to active levels. G1 – Minor geomagnetic storm conditions are likely October 17 from CME effects, with unsettled to active activity and a continued chance for G1 conditions on October 18. A transition to more nominal geomagnetic conditions is expected on October 19.