Electron 2 MeV Flux Alert issued on September 29, 2026

An Electron 2 MeV Integral Flux Alert was issued on September 29, 2026, by the NOAA Space Weather Prediction Center. The alert was triggered after electron flux at energies greater than 2 MeV exceeded 1,000 pfu. This heightened flux event began at 15:35 UTC on September 26, 2026, and remains in effect, continuing an alert sequence from Serial Number 3747. The maximum measured flux reached 4,128 pfu at 14:40 UTC on September 28, 2026.

Elevated levels of energetic electrons in the outer radiation belt can pose an increased risk to satellites and spacecraft operating in geosynchronous orbit. Prolonged exposure to such elevated flux levels can enhance deep dielectric charging, potentially impacting satellite operations or instrument functionality. These alerts are relevant to satellite operators and space weather forecasters.

According to the latest forecast discussion from the NOAA SWPC issued on September 29, 2026, the greater than 2 MeV electron flux is expected to persist at high levels through October 1, 2026. No significant increase in solar proton flux has been observed, and geomagnetic and solar activity remain at low levels.