A severe solar storm is smacking Earth with a surprisingly big geomagnetic jolt, potentially affecting power grids and GPS tracking while pushing the colourful northern lights further south, US forecasters say.
This storm ranks 4 on the National Oceanic and Atmospheric Administration's 1-to-5 scale for geomagnetic effects. So far no damage has been reported.
Thomas Berger, director of the Space Weather Prediction Centre in Boulder, Colorado, said two blasts of magnetic plasma left the sun on Sunday, combined and reached Earth today much earlier and stronger than expected.
The storm, which could last for hours, can disrupt power grids only temporarily. Forecasters said auroras had already been seen in the northern tier of the US and may later be seen as far south as the middle United States.