We first reported on this possibility a few days ago.
On Feb. 12th, the magnetic canopy of sunspot AR2699 exploded–for more than 6 hours. The slow-motion blast produced a C1-class solar flare and hurled a coronal mass ejection (CME) almost directly toward Earth. This movie from the Solar and Heliospheric Observtory (SOHO) shows the CME leaving the sun:
The effectiveness of the CME could be enhanced by a stream of solar wind that was already en route to Earth when the sunspot exploded. The solar wind is flowing from a large wedge-shaped hole in the sun’s atmosphere. If the approaching CME sweeps up material from that stream, snowplow-style, it could strike Earth’s magnetic field with extra mass and potency.
Arctic sky watchers should be alert for auroras when the CME arrives. If the coming storm intensifies to category G2, observers in northern-tier US states from Maine to Washington could see auroras as well. Stay tuned for updates.
Story via NASA’s Spaceweather.com