Friday, September 12, 2014

Kp Index Reaches 7, then Storm Calms Somewhat

As predicted, the 0000 UTC estimated Kp index reached 7. There was a period of high-latitude G3 geomagnetic storming, which is currently over.  At 0300, estimated Kp was 4, right at the storm threshold.

Aurora watchers should still check the sky, because substorms are always possible.  Additional G3 storming is not out of the question, though the continued strong northward orientation of Bz makes it less likely than it would be if the interplanetary magnetic field were to turn south again.

In general, HF band conditions seem improved over this afternoon (U.S. time).