Northern lights may be visible as far south as Alabama, California

A powerful eruption from the sun is expected to supercharge the northern lights on Thursday evening, making colorful sky shows visible potentially as far south as Alabama and Northern California.

The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center said Thursday that plasma and other materials from the sun reached Earth at 11:17 a.m. ET, triggering what the agency called a “severe” geomagnetic storm.

These types of solar storms occur when eruptions from the sun, known as coronal mass ejections, hurl giant clouds of plasma into space. When directed at Earth, the plumes of charged particles collide with the planet’s magnetic field, interacting with atoms and molecules in the upper atmosphere to produce radiant auroras.

If conditions are clear, skywatchers in Canada and many northern U.S. states — including Alaska, Washington state, Idaho, Montana, North Dakota, Michigan, Minnesota and Wisconsin — will likely have the best views of the northern lights. Highly active auroras could also be visible in parts of Northern California, Nevada, Oklahoma, Alabama, Ohio, Pennsylvania and New York.

This week’s solar storm is the most severe since May 10, when the Space Weather Prediction Center observed an even stronger and much rarer solar storm. Before the May event, the NOAA had not issued a severe geomagnetic storm watch since 2005.