ST. LOUIS — A rare weather event is about to envelop the northern half of the U.S. on Thursday night, including St. Louis, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center.
The storm may bring "spectacular displays" of northern lights, or aurora borealis, as far south as Alabama, meteorologists said. It may also stress power grids already bearing the burden of back-to-back hurricanes in the Southeast.
The center issued a Severe (G4) Geomagnetic Storm Watch Wednesday morning. Several moderate to strong solar flares recently produced by a large sunspot cluster triggered the watch.
"A coronal mass ejection (CME) is an eruption of solar material," the center said on its website. "When they arrive at Earth, a geomagnetic storm can result ... The aurora may become visible over much of the northern half of the country, and maybe as far south as Alabama to northern California."
A watch issued at the "severe" level is very rare. Meteorologists issued the same watch last May, the first time such a watch was issued since 2005. The geomagnetic storm in May did bring the northern lights to St. Louis, which residents in rural areas even got pictures of.
Northern lights seen across St. Louis Friday night
Along with the northern lights, the storm may cause disruptions in communications, the electric power grid, navigation, radio, and satellite operations, meteorologists said.
"Only three Severe geomagnetic storms have been observed during this solar cycle which began in December 2019," the center said. "The last G5 (Extreme) was the Halloween Storms in October 2003. That G5 resulted in power outages in Sweden and damaged power transformers in South Africa."