Electron 2 MeV Integral Flux Alert issued on April 21

An Electron 2 MeV Integral Flux Alert was issued on April 21, 2026, after flux levels at geosynchronous orbit exceeded the 1,000 pfu threshold. This ongoing alert began on April 19, 2026, at 19:20 UTC and was continued following a maximum measured flux of 1,344 pfu on April 20, 2026.

The main potential impact of this ongoing event is significant internal charging of satellite systems. This condition increases the risk to satellite operations, as high-energy electron flux can cause anomalies or damage to onboard satellite electronics.

According to the latest NOAA SWPC forecast discussion, the elevated electron flux levels are expected to persist at moderate to high levels through April 23, 2026. The forecast notes that solar activity remains low, and no Earth-directed coronal mass ejections (CMEs) have been detected during the current reporting period.