G3 (Strong) Levels Reached on 28 June

G3 (Strong) storm conditions were reached about 9:28am EDT on June 28th. The increased geomagnetic activity was in response to the arrival of a coronal mass ejection (CME) that departed the Sun on June 25th. The CME was associated with a large filament eruption and analysis indicated a possible Earth arrival as a glancing blow today. Indeed, a disturbance in the solar wind was observed by an observation satellite one million miles from Earth at 5:12am EDT. This was the leading edge of the CME and when it arrived at Earth, geomagnetic conditions quickly intensified and eventually reached G3 levels. The G3 Warning is in effect until 5:00pm EDT as CME passage is anticipated to continue through the day. There will likely be variable conditions of geomagnetic response during CME progression, so continue to monitor our SWPC webpage for the latest information and updates.