P1.4 Diagnosis of Banded Precipitation Patterns Associated with Extratropically Transitioning Tropical Cyclones Using Csi Theory

Conditional slantwise instability (CSI) is observed to occur in saturated, statically stable atmospheres where the horizontal wind increases in magnitude and veers with height. A complete background on CSI may be found in the compendium by Schultz and Schumacher (1999). Numerous studies in the midlatitudes (e.g. Sanders and Bosart 1985, Moore and Blakely 1988, Weismueller and Zubrick 1998) have shown that CSI locally enhances the intensity of convective bands found in the midst of a larger region of convection, resulting in locally heavy amounts of precipitation, and that CSI is often found in conjunction with isentropic upglide to the north of a warm frontal structure, usually during the winter months.