At about 6pm CST on March 6, there was a very powerful X 5.4 solar flare. This triggered a coronal mass ejection (CME). Indications were that the CME wasn’t squarely directed at Earth, but that a strong glancing blow to the Earth’s magnetosphere was possible. Here’s the data in Wolfram|Alpha for the flare:
There are two X-class flares during this time range. The effects of the first flare hit the Earth on March 7 and was a minor glancing blow, but caused a geomagnetic storm with effects visible in northern latitudes.
The second flare was much bigger and caused high-frequency radio blackouts and a proton storm. As a result of such events, satellites may reboot, and space crews may need added shelter.
The first flare has resulted in a K index of 6. It requires a minimum of 7 for auroras to be visible as far south as Chicago:
Because the CME can only be observed when it is near the Sun, estimates of the arrival time are based on its speed and direction at that time. As it gets further from the Sun, it becomes undetectable until it reaches our satellite monitoring stations near Earth. When will the CME hit? How strong will the effects be? Will it be dark at my location when there are auroras? These are all part of the waiting game when it comes to space weather.
The CME from the second flare was expected to hit around 12:30am CST on March 8 (± 7 hours). With a nearly full moon, it would have to be really bright to be seen, since the sky glow from the Moon won’t help things. As of this morning at 5am CST, the CME had impacted the Earth’s magnetosphere, but the effects were initially weak. It is sparking a minimal geomagnetic storm. However, the storm could strengthen in the wake of the CME impact, so it’s still a good idea to keep a lookout.
The sunspot group that spawned this flare and CME is now better poised to throw a CME directly toward Earth, so even if this one doesn’t have any strong effect, the days ahead could still hold a chance.