A severe geomagnetic storm supercharged the northern lights Thursday evening, making the aurora borealis visible from parts of San Diego County for the second time this year. A storm strong enough to be visible from San Diego happens when eruptions from the sun send clouds of plasma toward Earth. Those particles interact with elements in the Earth’s atmosphere to create streaks of vibrant color, NBC 7 Meteorologist Brooke Martell said. When the particles interact with nitrogen, the geomagnetic storm appears red and when mixed with oxygen, they turn yellow and orange.