Properties of cold pools from PERiLS 2022-2023

Cold pools play a range of important roles in quasi-linear convective systems (QLCSs), including maintenance via the development of new convective cells as well as baroclinic generation of horizontal vorticity. Although a number of QLCS cold pools have been characterized in the literature using one or a few sensors, their variability (both internally and across a range of environments) has still not been widely studied. This knowledge gap extends particularly to high-shear low-CAPE (HSLC) convective environments common to the cool season in the Southeastern US, where the Propagation, Evolution, and Rotation in Linear Storms (PERiLS) field campaign was focused.  PERiLS specifically targeted environmental and storm-scale processes in QLCSs, including their cold pools. Our analysis focuses on the heterogeneity and temporal variability of cold pools across short time and spatial scales using numerous surface and sounding observations across five PERiLS QLCSs. The PERiLS cold pools are generally weaker than those previously studied in warm-season, midlatitude QLCSs, likely due to the lower CAPE and higher relative humidity values common to the HSLC environments during PERiLS. Nevertheless, the distributions of most PERiLS cold pool variables at least partially overlap with those of previously-studied QLCSs. The median PERiLS measurement reveals a cold pool that is ≅2.5 km deep, having a surface temperature decrease of ≅-6°C, and a peak outflow wind gust of ≅13 m s-1. In the spirit of a "cold pool audit", we present the internal and case-to-case variability of these particularly well-observed QLCSs.