High Quality Content by WIKIPEDIA articles! The March 18–24, 2012 tornado outbreak sequence was a long lasting tornado outbreak that occurred due to a slow moving, but powerful trough and cutoff low. The outbreak began in the Great Plains, where, over a two-day period, several tornadoes touched down, some of which were significant. The North Platte area was damaged an EF3 that was produced by a supercell that spawned many tornadoes throughout its lifespan. The tornadic activity then shifted the Southern United States over subsequent, particularly in Louisiana and Mississippi. These states were struck by a series of tornadoes for 3 days, most of which were relatively weak on the Enhanced Fujita Scale. However, a few reached EF2 intensity and caused considerable damage. Tornado activity continued across the Ohio Valley on the 23rd, with one confirmed fatality in southern Illinois.