An observational study of two derecho cases is being prepared. These derechos were both warm season derechos in the central U.S. The 29 May storm tracked from western Nebraska to western Iowa while the 25 June storm began in eastern Nebraska and ended in central Missouri. Both systems met the derecho criteria but were of different types. The 29 May case was a progressive derecho while the 25 June case was a serial derecho. A synoptic analysis of each storm is done using surface, upper air, and sounding data from real time sources as well as RUC analysis data to compare the storm environments. The structure of the storms is also studied using radar and satellite data to further understand the storms' evolution. Their environmental and structural similarities and differences are also being closely examined to help determine what factors may ontribute most to the lifecycle of these two types of derechos. Also of great interest is how these influence the derecho type, duration, and the intensity of the wind reports. The overall goal of this research is to use the results of this study along with a detailed radar analysis to gain insight into the processes important to downdraft formation which result in surface wind reports.