NOAA Issues G1 Geomagnetic Storm Watch for Sept. 8-9, With Slight G2 Risk
Updated
Updated · The Watchers · Sep 7
NOAA Issues G1 Geomagnetic Storm Watch for Sept. 8-9, With Slight G2 Risk
3 articles · Updated · The Watchers · Sep 7
Summary
Sept. 8-9 could bring isolated G1 geomagnetic storm periods as several coronal mass ejections are forecast to reach Earth, prompting NOAA’s Space Weather Prediction Center to issue a watch.
Low confidence in the timing and strength of those arrivals reflects uncertainty over how the CMEs interact and whether their magnetic fields turn strongly southward, a setup that would intensify geomagnetic activity.
Solar-wind conditions were already elevated on Sept. 7, with the interplanetary magnetic field reaching 18 nT, Bz dropping to -14 nT and wind speed peaking at 434 km/s.
G1 conditions can cause weak power-grid fluctuations, minor satellite effects and aurora at lower latitudes, while a separate fast CME seen on Sept. 7 was judged a farside event not headed for Earth.