Often precipitation systems are organized into banded structures. These structures include hurricane rainbands and precipitation bands associated with low pressure centers. Often the heaviest precipitation occurs in these bands. It is believed that banded structures are associated with instabilities in the atmosphere know as conditional symmetric instability (CSI). Using an advanced numerical model, the Principal Investigator will continue a line of research that involves assessing various atmospheric forcing terms and how they effect the CSI. Special attention will be paid to radiation and surface forcing terms If successful, this research will provide better understanding and potentially better prediction of banded precipitation structures.