Overview

• An unexpectedly strong G3 geomagnetic storm overnight Sept. 29–30 pushed the Kp index to about 7.33, producing auroras visible before sunrise across parts of New England and Alaska, according to Spaceweather.com and NOAA’s SWPC.
• Photos and videos documented vivid displays from Mount Washington, N.H., and Mount Katahdin, Maine, around 5:30 a.m., with additional sightings in Vermont, northern North Dakota, and Scarborough in North Yorkshire, UK.
• NOAA says the disturbance followed an M6.4 solar flare from an active region on Sunday, with a coronal mass ejection likely clipping Earth as effects persisted into Tuesday before weakening.
• The reach exceeded earlier guidance that placed the auroral viewline near the U.S.–Canada border, underscoring short‑term forecast uncertainty during heightened solar activity.
• Aurora chances remain elevated in the post‑equinox period and during Solar Cycle 25’s peak into early 2026, so observers should monitor NOAA’s 30‑minute and 3‑day forecasts or trusted aurora apps for updates.