Intra-cloud lightning activity often precedes the first cloud-to-ground strike in a thunderstorm. In this case, a squall line was approaching northwest Alabama and the Muscle Shoals TAF site. The cloud-to-ground lightning observations (on the left) indicate that lightning activity is confined to the main squall line. However, the intra-cloud observations by the lightning mapping array indicate that preceding convection ahead of the squall line are already electrically active and that the cloud-to-ground threat is imminent. These preceding storms produced cloud-to-ground lightning five minutes after these observations.