Alert – Electron 2 MeV Integral Flux exceeded 1,000 pfu on September 11

An alert for Electron 2 MeV Integral Flux exceeding 1,000 pfu was issued by NOAA SWPC on September 11, 2026 at 00:45 UTC. The continued alert follows Serial Number 3739, with conditions beginning at 13:04 UTC on September 10, 2026. The alert was based on observed high electron flux levels, with a maximum of 3,080 pfu recorded at 17:45 UTC on September 10.

High electron flux conditions such as these can pose risks to spacecraft operations, including deep dielectric charging and potential damage to satellite systems operating in geosynchronous orbits. According to NOAA Space Weather Scales, alerts are issued when electron flux levels exceed 1,000 pfu at energies greater than 2 MeV. Proton flux remained at background levels, indicating no concurrent solar radiation storm activity.

Recent space weather observations indicated low solar activity, with only weak C-class flare activity detected from active regions on the solar disk. No major flares or significant coronal mass ejections immediately preceded the high electron flux event. The elevated electron levels are forecasted to persist at high levels through September 12 and are expected to return to low or moderate levels by September 13.