The last time I saw a notice like this was in March of 2001. The next few nights saw some of the most spectacular aurora displays in recent memory -- including reports of sightings as far south as Texas and Mexico.
I was in Sweden for that solar storm. The aurora was bright enough to read by, and to this day I swear I heard it - sounded like a distant faint buzzing or sizzling sound. It was beautiful and eerie.