
By Dean Murray
Scientists have warned the Sun has had a ‘severe’ storm that will affect Earth.
The US government’s scientific weather forecasting agency NOAA said Wednesday (Nov 12) a powerful geomagnetic solar storm reached G4 levels.
A G4 geomagnetic storm is classified as ‘severe’ on the five-level NOAA scale, where G1 is minor and G5 is extreme.
When a storm reaches G4, it indicates that the disturbance in Earth’s magnetic field caused by solar activity is strong enough to potentially cause widespread problems.
Such storms can disrupt satellite operations, GPS navigation and high-frequency radio transmissions, as well as trigger vivid auroral displays visible far beyond polar regions.
The X5.1 solar flare that caused the G4 geomagnetic storm is the strongest and most powerful solar flare of 2025 so far, and the most intense since October 2024.
It erupted from sunspot region 4274 on Tuesday and was nearly five times stronger than previous flares from the same region earlier in the week.
It produced a fast, massive coronal mass ejection (CME) directed towards Earth. When a CME meets Earth’s magnetic field, it can trigger geomagnetic storms that can disrupt power grids, satellites, and radio signals.

