Geomagnetic K-index of 4 Alert issued on March 29, 2026

A Geomagnetic K-index of 4 Alert was issued on March 29, 2026, with the threshold reached at 02:59 UTC. The alert covers the synoptic period from 00:00 to 03:00 UTC and indicates active geomagnetic conditions. The warning is currently active as per the official notification from NOAA SWPC.

Potential impacts of this alert are expected primarily poleward of 65 degrees geomagnetic latitude. These impacts include weak power grid fluctuations due to induced currents, and the possibility of aurora being visible at high latitudes such as in Canada and Alaska. These effects are consistent with the K-index reaching a level of 4, as described by space weather scales maintained by NOAA SWPC.

The alert follows a period of mostly quiet to unsettled geomagnetic conditions. The most recent SWPC forecast discussion reported that solar wind parameters reflected a nominal regime until a weak enhancement in the interplanetary magnetic field began late on March 28, with total field increasing to 7 nT and the Bz component deflecting southward. These changes contributed to the observed geomagnetic activity as captured by the K-index alert.