Space weather forecasters say a severe solar storm heading to Earth could stress power grids even more as the U.S. deals with major back-to-back hurricanes.

The storm also may trigger northern lights as far south in the U.S. as the lower Midwest and Northern California, though exact locations and times are uncertain.

A massive ball of plasma and accompanying magnetic field ejected from the Sun is expected to strike Earth on Thursday morning, potentially triggering auroras as far south as Alabama, according to US forecasters.