Northern lights may be visible from 19 U.S. states this week.

NOAA predicts a moderate to strong geomagnetic storm that could make the northern lights visible across about 19 U.S. states late on March 18 into the early hours of March 19, with best viewing generally between 10 p.m. and 2 a.m. local time.

NOAA forecasts a moderate to strong geomagnetic storm that could make the northern lights visible across parts of the United States late on Wednesday, March 18 into the early hours of Thursday, March 19. The possibility is linked to stronger auroral activity around the March 20 spring equinox, when an "equinox effect" can allow charged particles to intensify displays. How far south the aurora will be visible depends on whether the storm reaches G2 (moderate) or G3 (strong) levels and on local weather and light conditions. NOAA's Space Weather Prediction Center is posting updates and an Aurora Dashboard with current forecasts. Key details: - NOAA predicts a moderate to strong geomagnetic storm centered on March 18–19 that could push auroral displays farther south than usual. - About 19 U.S. states have at least a chance of seeing the aurora on those dates, potentially as far south as Illinois and Oregon depending on storm strength. - Best general viewing times are typically between 10 p.m. and 2 a.m. local time, though this can vary by location. - The March 20 spring equinox and the related "equinox effect" are expected to increase auroral activity by aligning conditions that let charged solar particles interact more strongly with Earth's magnetic field. - NOAA's Aurora Dashboard and space weather updates will carry the most current information about storm strength and likely visibility. Summary: The forecasted geomagnetic storm could extend auroral visibility into regions farther south than usual, giving more areas a chance to observe the northern lights. Local conditions, including whether the storm reaches G2 or G3 levels and weather or light pollution, will determine actual visibility. NOAA will continue to update forecasts on its Aurora Dashboard.