March 12 2006 was the classic situation where two big storms merge to form a monster supercell. It took almost the same path as the supercell back in April 1996 except this storm traveled from as far as northern Oklahoma. Thats a very long time for a storm complex to stay together. The March 12 2006 supercell produced an EF-2 tornado that hit in Springfield Illinois causing major damage. Tornadoes were also reported in other parts of Sangamon County, Greene County, Morgan County, Logan County, Scott County, northwest Macon County and southern Dewitt County. RFD winds were also causing significant damage and other problems throughout the area. This historic storm layed its mark on Central Illinois...

On April 19th 1996 an outbreak of tornadic supercells occurred in central and northern Illinois.  The total of 36 tornadoes in Illinois set a single day record, and exceeded the number expected in an average year. The storms formed along both a surface drytrough and warm front. The convection along the drytrough was observed, after a period of splitting and merging, to then move off the boundary into central Illinois and become tornadic. In Illinois, 31 counties sustained damage, one fatality and $30 million in damage was reported.