The Space Weather Prediction Center (SWPC) said today that G4 (Severe) geomagnetic storm levels were observed at 2350 UTC on September 7 and again at 0151 UTC and 1304 UTC on September 8, due to the effects of a coronal mass ejection (CME). A G3 (Strong) or greater warning was in effect until 1500 UTC today.
Solar flares have adversely affected HF nets attempting to gather information on the three current active hurricanes.
A G4 storm can cause widespread voltage-control problems, and some protective systems may mistakenly trip out key assets from the power grid. HF radio propagation will be sporadic, satellite navigation degraded for hours, low-frequency radio navigation disrupted, and aurora may be seen at lower-than-typical latitudes.