The big aurora blast we were waiting for appears to have fizzled with only a minor spike in activity. But the sun has more in store. Wednesday’s giant X9.3 flare in sunspot group 2673 sparked a coronal mass ejection (CME) that’s arrived sooner than expected. It slammed Earth’s magnetosphere around 6 p.m. (Central time) this evening and immediately started making beautiful mischief.
The Kp index shot up to “8” at 7 p.m. CDT and is still pinned there as of 10 p.m., making this a G4 SEVERE STORM. The Bz, a measure of the direction of the particle cloud’s magnetic field, stood at —28 at 6:30 p.m. This indicates a steep, southward tilt, the ideal direction for the swarms of electrons and protons to link up with Earth’s field and whip up auroras.
The first auroral fingers dappled the northern sky even in twilight as seen from Duluth, Minn. Between 8:30 and 9 p.m., rays reached to the zenith in a brief coronal display. Hopefully, activity will continue throughout the night though the moon will become more of a bother. Please let us know if you see the aurora via the comments link or just send me an e-mail at: firstname.lastname@example.org
The aurora forecast was for a moderate G2 geomagnetic storm over U.S. time zones starting at nightfall, but as of 10 p.m. CDT, it’s still rated as a G4 storm. More moderate to strong storms are expected both Friday and Saturday nights.
Hang on, we’re gonna surf this solar wind for a while!