Easy Aurora: Forecast & Alerts

Solar wind, rebuilt The animation now shows the real coronal mass ejections heading for Earth: where each one has got to, and how long before it arrives. • Several clouds are often in flight at once — all of them are drawn. • Colour says how strong: a weak one stays quiet, a real storm shows. • Tap for the detail: speed, direct hit or glancing blow, Kp expected. Arrival times now come from NOAA's own propagation, which also sharpened the charts.