A G3-class solar storm (i.e., a big one) is predicted to hit the earth tonight, generating category 7 aurorae, which are rarely seen on earth:
Auroral activity will be high(++). Weather permitting, highly active auroral displays will be visible overhead from Inuvik, Yellowknife, Rankin and Igaluit, to Portland OR, Cheyenne, Lincoln, Springfield, and New York City, and visible low on the horizon as far south as Carson City, Oklahoma City, and Raleigh.
Here's the prediction map from the University of Alaska at Fairbanks:
But here's the observed aurora right now:
So, while the aurora isn't yet visible in Chicago, the solar storm might propel enough material into our ionosphere that we could see some auroral displays in a few hours—or tomorrow. The prediction for Tuesday calls for displays overhead central Wisconsin which would be visible down to St. Louis, weather permitting.
The only place in Chicago dark enough to see them is the lakefront. Parker and I might have to walk over there tomorrow evening.
Updates as events warrant...