Bob Moler's Ephemeris Blog

On Thursday the 19th a CME (Coronal Mass Ejection) erupted from the sun headed earthward. Generally these things take about 2 days give or take to get to the earth. When they do they tangle with the earth’s magnetic field and cause huge currents to flow toward the earth’s magnetic poles causing among other things the aurora or northern and southern lights.
So check the skies tonight, especially northward if you are in the northern hemisphere or southward if you’re in the southern.
The higher your latitude the better your chances of seeing it. But who knows. Check out http://spaceweather.com/.