Aurora Forecast Site

Auroras are forecast for tonight, the 17th, as far south as the
Iowa-Minnesota border, but the main areas will be
in the green band.

Here is a site that forecasts the extent of auroras. A friend writes:  thick green band over Alaska and Canada is indication of where the Aurora will be seen directly overhead. The narrow green line to the south indicates the geographic areas where the Aurora will be visible over the horizon.