The last time a severe geomagnetic watch like this was issued, the aurora borealis danced above the St. Louis region’s skies.

ST. LOUIS — A rare space weather event is forecast to envelop the northern half of the U.S. on both Tuesday night and Wednesday night. It may even affect St. Louis’ skies.

The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center on Tuesday issued a Severe (G4) Geomagnetic Storm Watch alert. An eruption of solar material and magnetic fields from the Sun’s surface is forecast to hit Earth Tuesday night into Wednesday and is expected to generate spectacular displays of the aurora borealis, or northern lights, throughout northern states.

The best chance to see the northern lights in Missouri is Tuesday night, according to the 5 On Your Side Weather Impact Team. Communities near Missouri’s northern border have the best chance of seeing it with the naked eye, while every other resident in the state will likely need a camera.

“Most likely people will need to use long exposure on the camera, but there is a chance it could be faintly visible to the naked eye if it is strong enough,” 5 On Your Side’s Chief Meteorologist Scott Connell said.

NOAA also warned that the geomagnetic storm may detrimentally impact critical infrastructure, but mitigation is possible. The U.S. Department of Homeland Security’s website lists canceling maintenance work and re-routing load as possible mitigation options, but said that’s only possible with geomagnetically inducted currents forecasts at the local level, which currently has very limited capabilities. 

A watch issued at the “severe” level is very rare, with only four such watches being issued so far this solar cycle, according to NOAA. A similar watch was issued for the St. Louis region in October 2024, which also resulted in beautiful northern lights displays across the area.

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Take a look at some of the photos sent to 5 On Your Side the last time a vivid northern lights display hit St. Louis’ skies:

Northern Lights across Missouri and Illinois on Oct. 10, 2024