There is a high probability of a moderate geomagnetic storm hitting Earth over May 9th through 10th in the wake of two coronal mass ejections (CME) and a coronal hole spewing solar wind in the planet’s direction.
The two CMEs erupted from the Sun on May 7, from a sunspot region that is so large it is visible without aid of a telescope. Sunspot AR1476, one of a group of four spots larger than Earth, is expected to be a source of X-class solar flares, the most severe and hazardous classification.
The latest flares coincide with a coronal hole pointed in the direction of Earth. A coronal hole is a gap in the Sun’s magnetic field that allows solar atmosphere to escape. The resulting outflow of gases constitutes solar wind. This wind is the cause of the vivid auroras seen the evening of May 8 over northern latitudes.
In addition to auroras, the increased solar activity may present a threat to space based assets including communication and navigation satellites and the International Space Station crew. More severe storms can impact terrestrial electrical grids and interfere with commercial airliner routes in northern latitudes.