Strong Geomagnetic Storm May Bring Northern Lights Over Washington

SEATTLE — The Nothern Lights could be visible as far south as the Oregon border Wednesday night, thanks to the anticipated arrival of several coronal mass ejections from the sun. The Space Weather Prediction Center issued a "G3" geomagnetic storm warning Tuesday, with aurora activity most likely to ramp up Wednesday evening.

If the forecast holds, Puget Sound communities will have a much better chance than usual to catch a late-night glimpse of the Northern Lights. G3 storms are the third-strongest on the Space Weather Prediction Center's five-point scale, and considerably more rare than the minor G1 storms that typically bring light aurora activity over parts of Western Washington a few times a year.

"When the [coronal mass ejection] approaches Earth, NOAA’s DSCOVR satellite will be among the first spacecraft to detect the real-time solar wind changes and SWPC forecasters will issue any appropriate warnings," the Space Weather Prediction Center wrote Tuesday. "Impacts to our technology from a G3 storm are usually minimal. However, a G3 storm has the potential to drive the aurora further away from its normal polar residence, and if other factors come together, the aurora might be seen over portions of Pennsylvania, Iowa, to northern Oregon."

Space weather forecasters expect most of the ejections will miss Earth, but NOAA said its models showed at least four could be on track to make contact Wednesday night, presenting the best chance for widespread aurora viewing. A second show could be in the cards, too. A G2, or moderate, geomagnetic storm watch will remain in place through Thursday.

There is a potential for clouds increasing in Seattle overnight Wednesday, but full cloud cover is not in the current forecast. As usual, the best chance to see the aurora is in places away from city lights and with a clear view of the northern horizon.

The Space Weather Prediction Center regularly updates its aurora forecasts online.