spaceweather.com

THE CME HAS ARRIVED: The first of two CMEs heading toward Earth has just arrived. It struck our planet on Dec. 31st at 1621 UTC, causing a 17 nT jolt in the USGS's Boulder magnetometer. The impact does not appear potent enough to cause a strong (G3) geomagnetic storm. Instead minor (G1) to moderate (G2) storms are possible in the hours ahead.