S1 – Minor Solar Radiation Storm Alert issued on July 30

An S1 – Minor Solar Radiation Storm Alert was issued on July 30, 2026, after the 10 MeV integral proton flux exceeded the 10 pfu threshold. The alert began at 19:03 UTC and was classified under the S1 – Minor category according to the NOAA Space Weather Prediction Center.

The S1 – Minor Solar Radiation Storm level typically indicates minor impacts on satellite operations, with increased noise in imaging systems and possible effects on high-altitude polar flights. Biological impacts on the general population are considered negligible during an S1 event.

According to the latest SWPC forecast discussion, solar activity has been at low levels over the preceding 24 hours, with the largest recorded flare being a C3.8-class event. No Earth-directed coronal mass ejections were reported in connection with recent eruptions, and the greater than 10 MeV proton flux had previously remained at background levels.