ALERT: Geomagnetic K-index of 4 Alert issued on November 2

An ALERT: Geomagnetic K-index of 4 was issued on November 2, 2025, after the threshold was reached at 17:49 UTC. The alert covers the synoptic period from 15:00 to 18:00 UTC and was officially issued at 17:55 UTC by the NOAA Space Weather Prediction Center. This alert indicates increased geomagnetic activity, though not reaching G1 – Minor Geomagnetic Storm levels.

Potential impacts are expected primarily poleward of 65 degrees geomagnetic latitude. Weak power grid fluctuations may occur due to induced currents. Additionally, auroras may be visible at high latitudes, such as in Canada and Alaska.

According to the latest forecast discussion, geomagnetic activity has been elevated due to ongoing effects from a coronal hole high-speed stream (CH HSS). Solar wind parameters have been gradually decreasing, and the geomagnetic field has been reported at unsettled to active levels. There is also a low-confidence possibility of weak enhancements from the periphery of a coronal mass ejection (CME) that left the Sun on October 30. The geomagnetic field is forecast to range from quiet to active through November 3 as these influences wane.