Tweet Supercell hailstorm with extreme lightning and giant hailstones Supercell Hailstorm. On the 3rd December 2016, a major supercell developed under extreme instability in northern NSW. The storm then crossed the border and dumped significant sized hailstones at Rathdowney. During this phase, the storm was extremely lightning active with lightning produced from the anvil as … Continue reading Supercell Hailstorm in S Queensland NE NSW