The NOAA Space Weather Prediction Center in Boulder, CO has updated its Geomagnetic Storm Warning for the weekend of May 10 – May 12, 2024. “Significant geomagnetic storming to persist this weekend”, the warning states. “There have been reports of power grid irregularities and degradation to high-frequency communications and GPS”. Aurora effects in the sky were observed as far south as Alabama and Florida.
A Level 6 K-index is expected through Saturday evening, which means the storm could impact the power grid at latitudes north of 55 degrees, which is north of the contiguous United States. The NOAA K-index “quantifies disturbances in the earth’s magnetic field with an integer in the range 0-9 with 1 being calm and 5 or more indicating a geomagnetic storm”. The last extreme (G5) event occurred in October 2003, resulting in power outages in Sweden and transformer damages in South Africa.
