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.

The NOAA said this geomagnetic storm is expected to last through Friday, with the possibility that it could still intensify.

But solar storms can have negative impacts. Strong eruptions aimed at Earth can cause disturbances in the planet’s magnetic field, knocking out power grids and damaging infrastructure.

The NOAA said the solar storm could affect ongoing recovery efforts following Hurricane Helene and Hurricane Milton across the Southeast if power grids are disrupted, communications systems are degraded or GPS satellites are knocked offline.

“Systems that depend on low-Earth orbit satellites or High-Frequency communication may experience disruptions,” the Space Weather Prediction Center said in an update on Thursday, adding that the agency has been in touch with FEMA and state officials.

The northern lights, also known as aurora borealis, are typically seen at high latitudes, but intense solar storms can make them visible much farther south than normal.

The sun goes through roughly 11-year cycles of activity, from minimum to maximum. It is ramping up toward an expected peak in July 2025, according to the NOAA, which is why skywatchers this year have been treated to several spectacular displays of the northern lights.

The NOAA maintains an aurora dashboard that provides short-term forecasts of the northern lights, including maps of where they will be visible and experimental tools that estimate their intensity.