The National Oceanic and Atmospheric Administration (NOAA) Space Weather Prediction Center has issued an outlook forecasting active to G1 storming levels for Earth's geomagnetic field on September 7-8. This anticipated activity is primarily due to the expected arrival of multiple Coronal Mass Ejections (CMEs) observed in the past week.
Solar activity from August 31 to September 6 was moderate, marked by three R1 (Minor) M-class flares. The largest, an M3.0 flare, originated from Region 4524 on September 2, accompanied by a CME. Another M1.0 flare from Plage Region 4520 on September 5 also produced a CME, which caused a rapid, albeit brief, enhancement in proton levels at geosynchronous orbit.
Several CMEs were observed, with modeling indicating potential glancing blows or merged arrivals at Earth. One CME from September 4 is expected to merge with an earlier eruption, potentially causing a glancing blow late on September 7 or early on September 8. Three CMEs from September 5 may have a merged arrival on September 8, with another from September 6 possibly arriving late on September 8 or early on September 9.
Beyond the immediate forecast, G1 storming levels are also anticipated for September 24-26 due to a recurrent positive polarity coronal hole high-speed stream. Active levels are expected on September 14-16 from a recurrent negative polarity stream. Solar activity is generally expected to remain low, with a chance for moderate to high levels throughout the forecast period.