Intercomparison Between Polarimetric Radar, Lightning, and Satellite Indicators of Storm Severity in a Tornadic Supercell

Comparisons are made between derived products from radar, satellite, and lightning data that act as indicators of storm severity and proxies for storm updraft strength in a tornadic supercell. The data that are analyzed include (i) satellite products developed to detect overshooting tops (OTs) and determine the amount of cloud-top cooling (CTC), (ii) a new, novel, polarimetric radar algorithm used to determine the heights of columns of enhanced differential radar reflectivity factor (Z_DR), and (iii) lightning data from a Lightning Mapping Array. All of these data can be used to infer changes in storm severity. Both OTs and large CTC rates are associated with rapid cloud growth and have previously been shown to be indicators of impending severe weather. The height of the Z_DRcolumn has been shown in both observational and modeling studies to be directly related to updraft speeds in the main storm updraft. Finally, an increase in total (in-cloud and cloud-to-ground) lightning flashes within a storm, a lightning jump, also has been associated with impending increases in storm severity.

However, the polarimetric radar and satellite/lightning products have not yet been compared to each other in supercells. The goal of this study is to (i) establish direct relationships between CTC values and Z_DR column height, (ii) evaluate changes, if any, in CTC values and Z_DR column heights when OTs and lightning jumps are detected, and (iii) determine how often the information from the different platforms is complementary. Optimally, in order to maximize the temporal resolution of the satellite data, the chosen case utilizes data from GOES-14 run in Super Rapid Scan Operations for GOES-R (SRSOR) mode. Of particular interest is how the values of these indicators of storm severity change leading up to important storm processes, including tornadogenesis.