'Severe' geomagnetic storm to slam Earth Thursday, possible as far south as California and Alabama

A powerful solar outburst is likely to trigger a "severe" geomagnetic storm on Thursday, with auroras potentially visible as far south as California and Alabama, NOAA predicts.

An enormous mass of charged solar particles will slam into our planet Thursday (Oct. 10), likely triggering a "severe" G4-class geomagnetic storm, according to an alert from the National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center.

Storms of this magnitude may disrupt power grids, nudge satellites off course, interfere with GPS navigation and damage "critical infrastructure technology," NOAA warns.

The geomagnetic storm will also make auroras visible at much lower latitudes than usual. According to NOAA, the northern lights "may become visible over much of the northern half of the country, and maybe as far south as Alabama to northern California" Thursday.

The solar outburst, known as a coronal mass ejection (CME), is the result of a powerful solar flare that erupted from our star on the evening of Oct. 8, according to NOAA. The flare has been categorized as an X 1.8-class solar flare, which is the strongest type of flare the sun can emit.

Solar flares occur when tangled magnetic-field lines on the sun violently snap back into place. Some flares may be accompanied by CMEs — fast-moving blobs of plasma that can take several days to reach Earth, if our planet happens to be within the firing line. Upon hitting our planet, CMEs can cause major disturbances in Earth's magnetic field known as geomagnetic storms, resulting in technological malfunctions and widespread auroras. NOAA measures geomagnetic storms on a scale of 1 to 5, with G1 storms considered "mild" and G5 storms dubbed "extreme."