Electron 2 MeV Integral Flux Alert issued on September 27

An Electron 2 MeV Integral Flux Alert was issued by NOAA SWPC on September 27, 2026, at 05:02 UTC. This continued alert indicates that the integral electron flux at energies greater than 2 MeV exceeded the threshold of 1,000 pfu, beginning at 15:35 UTC on September 26. The maximum recorded flux reached 1,260 pfu at 16:45 UTC on September 26.

Elevated levels of energetic electrons at geosynchronous orbit can lead to increased risks of deep dielectric charging on satellites. This may result in temporary anomalies or operational issues for spacecraft operating in affected regions. Effects are primarily of concern to satellite operators and do not directly impact terrestrial technologies or the public.

The heightened electron flux follows a period of mildly enhanced solar wind as coronal hole high-speed stream (CH HSS) influences weakened. The greater than 2 MeV electron flux reached high levels during this period and is forecasted to remain elevated through September 29. No Earth-directed coronal mass ejections were detected, and solar activity remained low with only minor flare activity reported.