Incoming Solar Storm May Ignite Auroras This Labor Day

FLAGSTAFF, Arizona — A powerful solar storm is expected to enhance the visibility of auroras across parts of the United States this Labor Day weekend.

The storm follows a long-duration M2.7 flare that erupted from sunspot Active Region 4199 on August 30. This event launched a fast-moving coronal mass ejection (CME) toward Earth, which is forecasted to arrive late on September 1 into early September 2 (UTC), according to NOAA‘s Space Weather Prediction Center.

NOAA modeling indicates that moderate (G2) geomagnetic storming is likely when the CME first strikes, increasing to strong (G3) levels as the bulk of the storm passes on September 2. This could allow for auroras to be visible more broadly across northern U.S. states than usual.

Space weather physicist Dr. Tamitha Skov pointed out that two Earth-directed solar storms are on course for collision. “The larger one is likely to catch up with the smaller one just as it approaches Earth,” she said. “Impact is expected by late September 1. G2+ conditions are possible,” Skov added.

This interaction, where one CME overtakes another, is commonly referred to as a “cannibal CME.” NOAA’s models suggest that significant enhancements to the auroral oval could occur following the CME’s arrival, potentially allowing visibility as far south as areas like East Anglia and the Midlands in the U.K., depending on clear skies.

However, viewers should be aware that a waxing gibbous moon might limit visibility. Historically, G3 storms can bring auroras to mid-latitude regions, including parts of Oregon, Illinois, and New York.

Geomagnetic storms occur in a scale ranking from G1 (minor) to G5 (extreme). Stronger storms can also interfere with satellites and radio communications, and they may cause fluctuations in power grids.

Conditions for auroras are anticipated to remain elevated through September 3, providing additional opportunities for skywatchers, even if clouds obstruct the view one evening.

For those in northern states, downloading space weather apps that offer real-time aurora forecasts can improve the chances of experiencing this stunning natural phenomenon. Recommended apps include “My Aurora Forecast & Alerts” and “Space Weather Live,” both available for various devices.