Aurora visible across northern U.S. and Alaska overnight

A potential display of the northern lights could light up the night sky across a broad swath of the United States, as a fast-moving solar wind interacts with Earth’s magnetic field to trigger a minor geomagnetic storm. Forecasters say the aurora could be visible from late tonight into the early hours of tomorrow in northern states and Alaska, with a favorable viewing window between roughly 11 p.m. and 5 a.m. local time under dark skies and minimal light pollution. The best chances are in northern regions, though a broader swath of the country could see faint greens and purples along the northern horizon if conditions cooperate.

The phenomenon arises when charged particles from the sun collide with gases in Earth’s atmosphere, producing the shimmering curtains of light known as the aurora borealis. The current event is driven by a high-speed solar wind stream emanating from a large open region in the sun’s magnetic field, called a coronal hole. When these charged particles reach Earth, they can disturb the planet’s magnetic field, producing geomagnetic activity that, in turn, can make auroras more visible at midlatitudes than usual. Forecasters monitor the situation with the Kp...