Northern Lights forecast may reach 18 U.S. states Wednesday

NOAA forecasts a moderate geomagnetic storm from a March 16 coronal mass ejection that could make the northern lights visible across roughly 18 U.S. states, with peak activity expected Thursday morning and best viewing hours around 10 p.m. to 2 a.m.

A moderate geomagnetic storm connected to a coronal mass ejection that left the Sun on March 16 is expected to reach Earth and could push aurora visibility south of the Canadian border. NOAA's Space Weather Prediction Center has forecast a Kp index of about 6 on a scale of 0–9 for the event. The timing of peak activity is expected in the early hours of Thursday morning, which may allow the northern lights to be seen in parts of the northern United States. Known details: - NOAA forecasts a Kp index of 6 due to a coronal mass ejection that departed the Sun on March 16. - The event is described as a G2-class geomagnetic storm at peak, with a possible G1-level storm the following night. - Forecasters say aurora visibility could extend into roughly 18 U.S. states, including northern parts of states such as Montana, North Dakota, Minnesota, Wisconsin, Michigan, Maine, Washington, New York, Nebraska and Iowa. - There is a reported 10% chance of a small solar radiation storm connected to this activity; such storms involve high-speed protons and are typically polar-focused. - Best viewing is usually after dark, roughly between 10 p.m. and 2 a.m., and visibility depends on local weather and light conditions. Summary: NOAA expects the geomagnetic disturbance to peak Thursday morning and the aurora may be visible at lower-than-usual latitudes as a result. Possible secondary effects on space and high-altitude operations are noted in forecasts; further details and day-to-day forecasts will come from NOAA as the event unfolds.