A severe geomagnetic storm could bring northern lights as far south as Alabama Sunday and Monday.

NOAA’s Space Weather Prediction Center issued a Geomagnetic Storm Alert on Sunday due to a larger-than-expected eruption resulting in a solar flare. The storm was originally rated as a minor G1 or G2 storm on the National Oceanic and Atmospheric Administration’s five-point scale but was later upgraded to a G4 storm, the New York Post reported.

A G1 rating is credited for producing the common auroras over Alaska and Canada. Under the right conditions, G3 ratings can produce auroras to be seen as far south was Washington, Wisconsin and New York. Fox Weather reported a G4 storm – predicted to last through Monday – could make Northern Lights visible as far south as Alabama and northern California.

Cloud cover can impact what people in the south will be able to see, though a faint light may be visible late Sunday into Monday. It’s more likely the furthest south the lights will be seen is northern Illinois and central Iowa.

No adverse effects from the magnetic storm are expected though NOAA said there is an increased possibility of effects on satellite operations or issues with GPS.

Aurora is the name given to the flow or lights produced when electrons from space flow to Earth’s magnetic field and collide with atoms and molecules of the atmosphere in a run or oval centered on the magnetic pole of the Earth, NOAA explains. The collisions produce lights similar to how electrons flowing through gas in a neon light collide with neon and other gasses to create colored light bulbs.

Technically called Aurora Borealis, aurora is called the Northern Lights in the northern hemisphere and Southern lights in the southern hemisphere. The biggest and most active auroras are produced by Coronal Mass Ejections like the one that occurred this week, NOAA said.