Solar Storm Today: Will a CME Hit Earth and Trigger Northern Lights? Latest Forecast
A coronal mass ejection linked to a powerful solar eruption is continuing to influence Earth’s space-weather outlook Saturday, Aug. 29, with NOAA forecasting periods of minor to moderate geomagnetic storm activity that could give skywatchers in far northern areas another chance to see the northern lights.
The latest NOAA forecast, issued early Aug. 29, calls for G1 to G2 geomagnetic storm conditions during the day as high-speed solar wind from a coronal hole combines with the expected influence of CMEs launched from the Sun on Aug. 25-26.
The forecast’s strongest three-hour periods reached a predicted Kp of 5.67, equivalent to a G2 moderate geomagnetic storm.
Will the CME Hit Earth Today?
The answer is potentially yes, and the space-weather event is already being monitored as part of the current geomagnetic activity.
The activity traces back to Aug. 25, when active sunspot region AR 4513 produced an M6.9 solar flare.
The eruption was accompanied by a CME with an Earth-directed component.
A second eruption associated with a C4.7 flare and filament eruption also produced material headed partly toward Earth.
Earlier forecasts warned that the bulk of the CME material could miss Earth, but that a glancing encounter could still raise geomagnetic activity.
The British Geological Survey similarly assessed the CMEs as having the potential for a glancing blow while forecasting G2-level activity for Aug. 28-29.
A CME does not automatically produce a major aurora display.
Its magnetic orientation and interaction with Earth’s magnetic field determine how strongly the planet responds.
Northern Lights Forecast for Aug. 29
NOAA’s latest three-day forecast calls for the greatest geomagnetic activity on Aug. 29 to reach Kp 5.67, or G2, with G1-level conditions also possible as the day progresses.
The forecast then trends toward quieter conditions on Aug. 30 and Aug. 31.
The strongest activity is expected at high geomagnetic latitudes, meaning Alaska and northern Canada are among the better-positioned areas in NorthAmerica.
Under stronger-than-expected conditions, the auroral oval can expand farther south, but a G1-G2 storm does not guarantee that the lights will be visible from every northern U.S. location.
EarthSky reported Aug. 28 that fast solar wind had begun reaching Earth and that another burst of solar material was expected to arrive, keeping aurora chances alive.
What Caused the Solar Storm?
The chain of events began with the M6.9 flare from AR 4513 on Aug. 25.
The flare peaked at about 10:02 UTC and produced an R2, or moderate, radio blackout across portions of the sunlit side of Earth, including areas of Africa, Europe and the Arctic.
A solar flare is a burst of electromagnetic radiation.
A CME is different: it is a huge cloud of magnetized solar plasma traveling through space.
When an Earth-directed CME reaches Earth’s magnetic field, it can trigger a geomagnetic storm and energize particles that produce auroras.
The Sun was particularly active around the eruption, with AR 4513 producing multiple M-class flares in a short period.
Could the Northern Lights Be Visible Farther South?
Possibly, but the current forecast does not support promising a widespread display across the United States.
A G2 storm can push auroral activity farther toward lower latitudes than during quiet conditions.
However, visibility depends on the storm’s actual strength, the orientation of the incoming magnetic field, local darkness and cloud cover.
FOX Weather noted that early modeling suggested a glancing CME impact and emphasized that the CME’s magnetic-field interaction with Earth would determine the timing and intensity of the resulting geomagnetic activity.
For anyone hoping to see the aurora Saturday night, the best strategy is to get away from city lights, find a location with a clear view toward the northern horizon and monitor updated aurora forecasts rather than relying on the original Aug. 27-28 predictions.
The immediate threat from this event is space weather, not a conventional storm on Earth’s surface.
Stronger geomagnetic storms can interfere with high-frequency radio communications, satellite operations, navigation systems and, at higher levels, electrical infrastructure.
The Aug. 29 NOAA forecast indicates the storm risk should gradually ease, with lower geomagnetic activity expected Sunday and Monday.
