Early cell evolution and resultant isolation of two long-lived supercells during the 12 March 2006 Tornado Outbreak

On 12 March 2006 a major tornado outbreak occurred across the lower Missouri River and mid-Mississippi River regions with scores of tornado, large hail and high wind reports. Of particular interest on this day was the early evolution of two long-lived supercells that eventually produced numerous tornadoes. The southernmost of these supercells traversed four states and had a life span exceeding 11 hours. A relatively small number of past studies have documented the sometimes very complex early evolution of groups of cells forming within a short period along a common boundary which resulted in one or more isolated supercells. This case provides an ideal opportunity to investigate this isolation process. Preliminary tracking analysis reveals an intricate process of cell interaction and attrition which produced these two isolated supercells. Of the numerous cells developing around noon CST in southeast Kansas and northeast Oklahoma, the cells that would become supercells generally formed earlier than neighboring cells and were the first to indicate reflectivity values exceeding 50 dBZ. These embryonic supercells gained a competitive advantage over their neighboring cells in terms of being the dominant cells in downstream interactions. We will present an investigation of the early evolution of the convection on this day including a detailed tracking analysis with an accounting of the evolution of all the cells forming within a prescribed initiation window in the region of interest.