Three CMEs Reach Earth, Capping Geomagnetic Storm at G2 After 12:30 a.m. Delay
Updated
Updated · The Boston Globe · Jun 4
Three CMEs Reach Earth, Capping Geomagnetic Storm at G2 After 12:30 a.m. Delay
2 articles · Updated · The Boston Globe · Jun 4
Summary
NOAA said the three coronal mass ejections finally reached Earth around 12:30 a.m. EDT Friday, but the event only climbed to a G2 geomagnetic storm Friday afternoon instead of the stronger levels once watched.
An unfavorable magnetic-field orientation blunted the impact: the CME field mostly matched Earth's overnight rather than opposing it, limiting the magnetic connection needed to drive G1-G3 storm conditions and brighter aurora.
Forecasters said the incoming magnetic cloud is now variable, so parts of New England could still see G1-G2 conditions Friday night, while G3 has become less likely and the duration remains unclear.
The miss underscored how hard CME forecasting is, because storm strength and aurora reach cannot be pinned down until satellites sample the solar wind about 1 million miles from Earth.