Estimations of CIN and LFC Associated with Tornadic and Nontornadic Supercells

Abstract

Abstract It is generally understood that tornadoes are less likely in environments where surface-based instability is absent and the only convective available potential energy (CAPE) is from elevated parcels originating well above the surface. However, little research has been done to examine tornado occurrence in environments where surface-based CAPE is clearly present, but located above a deep layer of surface-based convective inhibition (CIN) associated with a relatively high level of free convection (LFC) heights. A database of 518 model analysis soundings was collected during 2001–03 from recent versions of the rapid update cycle (RUC) analysis and forecast system. All model sounding profiles were in proximity to selected supercell storms associated primarily with tornado warnings, and were “nonelevated” with surface-based CAPE present. This database is used to examine CIN and LFC to determine environments where instability from mixed-layer and surface-based parcels was associated with significant ne...