I was trying to find stuff around Oct 2003 when the last event of this magnitude took place, but I wasn't able to find anything comparable. From what I can tell the forecast is more mild on the 12th UTC, so I wouldn't worry that much about that. I was worried in my case because my flight leaves pretty much at the apex of the geomagnetic storm.

I think we can expect delays, GPS being unresponsive, radio issues, and some control tower congestion & issues. Can't really comment with any more detail.