S4 (Severe) Solar Radiation Storm in Progress, January 19th, 2026

An S4 (Severe) solar radiation storm is in progress.

• NOAA's GOES-19 satellite measurements show the ongoing solar radiation storm has intensified to Severe (S4) on the NOAA Space Weather Scales, and it is still increasing.

• A Severe (S4) radiation storm is a rare event and exceeds the intensity during the October 2003 "Halloween" space weather storms.

• Potential Impacts:

  • Increased radiation exposure risk for astronauts and flights on polar routes.

  • Enhanced risk to satellites, especially those in geostationary orbit, and space launch systems.

  • Loss of over-the-horizon high-frequency communications in polar regions.

• SWPC has notified airlines, FAA, NASA, FEMA, NERC, and other stakeholders to support preparedness actions as conditions evolve.

This significant level has not been observed since October, 2003. Potential effects are mainly restricted to aviation polar routes, high frequency (HF) radio communications in polar regions,