Three solar flares erupted from sunspot region 4455 within a 24-hour period, prompting a federal environmental and scientific agency to issue a level 3 Geomagnetic Storm Watch. The space weather forecasting center predicts that coronal mass ejections from these flares will combine into a single plasma mass before reaching Earth.
The first flare, an M9.3-class event, peaked at 9:36 p.m. EST on June 2. A second flare, M7.9, occurred at 3:00 a.m. EST, followed by an X1.0-class flare that peaked around 7:30 a.m. ET. X-class denotes the largest category of solar flares, which release electromagnetic radiation, including X-rays and ultraviolet light, into space.
The space weather forecasting center predicts the merged solar material will arrive at Earth between mid-day on June 4 and mid-day on June 5. "There is a fair level of confidence about an Earth arrival." The space weather forecasting center said in an advisory. Forecasters indicate that the exact intensity of the incoming geomagnetic storm and its terrestrial impact remain uncertain.
Geomagnetic storms are rated on a scale of 1 to 5. A level 3 geomagnetic storm can lead to aurora visibility in states including Oregon, Washington, Illinois, Massachusetts, and New York. These storms can also disrupt telecommunications networks, satellite operations, radio transmissions, electric power grids, and navigation systems. High-energy solar emissions may also damage spacecraft and present safety hazards to astronauts.
The initial solar flares caused radio blackouts across Europe, Africa, Australia, and Asia. Space weather physicist Tamitha Skov stated, "Region 4455 continues to grow in complexity, so X-flare risk will remain elevated over the next 72 hours at least." She also noted earlier that "Region 4455 strikes again."