The Space Weather Prediction Center says that the storm is from sun activity that started on March 15.
It warned that there could be possible widespread voltage control problems at power systems and some protective systems could trip out key assets from the grid in the affected areas, which include areas of Canada and Alaska.
Spacecraft could also experience surface charging and tracking problems and corrections may be needed for orientation problems.
It warned that satellite navigation systems could be affected for hours and low-frequency radio navigation disrupted.
It also said that the aurora could be seen as far south as California because of the storm. Images on Twitter showed it was visible in the pre-dawn hours in Washington state.
A less severe storm hit Earth on January 7. That storm was classified as a G3.
Original Article: http://www.myfoxny.com/story/28540300/powerful-space-storm-hits-earth