Portland, Oregon – A space weather alert is in effect tonight as a rare G4 (Severe) geomagnetic storm creates the potential for Northern Lights to be visible across parts of Oregon, according to the NOAA Space Weather Prediction Center.
NOAA’s latest aurora forecast shows the auroral oval expanding well south of its usual range, placing northern Oregon and parts of central Oregon within reach of possible aurora visibility late tonight. Forecast guidance indicates a Kp index near 7 to 8, a level capable of producing auroras across the Pacific Northwest during strong solar storms.
The aurora occurs when charged particles from the Sun collide with oxygen and nitrogen high in Earth’s atmosphere, producing glowing green and red light displays. This activity is being driven by a coronal mass ejection currently interacting with Earth’s magnetic field.
For viewers in northern Oregon, including areas near the Columbia River Gorge, Mount Hood region, and coastal headlands, auroras may appear as faint bands or shimmering green light in the northern sky, especially in darker rural locations. Farther south, including central Oregon, the lights are more likely to appear as a subtle glow low on the northern horizon.
Visibility in Portland and other urban areas may be limited by cloud cover and light pollution, but brief breaks in clouds could still allow for faint aurora viewing.
The best chance to see the aurora is expected late tonight through the early morning hours, generally between 10 p.m. and 2 a.m., weather and cloud cover permitting. Observers are encouraged to seek dark locations, avoid city lights, face north, and allow time for eyes to adjust.
Auroras are harmless to people on the ground, though the same geomagnetic storm is prompting monitoring of satellites, GPS systems, and power infrastructure.
Auroral visibility may fluctuate overnight as geomagnetic conditions evolve.
