On Aug. 5th, a solar wind stream hit Earth's magnetic field, sparking G1-class geomagnetic storms and auroras in the USA. It's about to happen again. The same hole in the sun's atmosphere that wind-blasted Earth in early August is facing our planet today. Gaseous material emerging at 600 to 700 km/s could reach Earth as early as Aug. 31st, although Sept. 1st is more likely. NOAA forecasters say there is a chance of G2-class geomagnetic storms when the solar wind arrives.