Characterization of warm season convective systems over US in terms of Cloud to Ground lightning, cloud kinematics, and precipitation

Convective systems are tracked for two summer months over the continental USA and their properties at different stages of life are investigated in terms of Cloud to Ground (CG) lightning flashes, cloud kinematics, and precipitation. The study employs lightning data from the National Lightning Detection Network (NLDN) along with 1/2-hourly satellite Infrared observations, and hourly rainfall accumulation fields from the nationwide WSR-88D radar network. Results show strong dependence of the amount of CG lightning flashes with the stage of the storm's life cycle. The highest number of CG lightning flashes and highest area expansion rates are also seen to be during the growth stage of the systems. The stronger the lightning density, or cloud top area expansion rate, of the storms at their initiation stage is the longer is shown to be their life duration. The average rainfall yield per flash in the growing, mature and dissipation stages of storms with duration greater than 4 h is 4.7, 12.5 and 8.5 107 kg, respectively. The temporal evolution of the storms' area and CG flash rate are shown to correlate well with the evolution of rainfall parameters, such as storm's rainfall yield (m3), conditional mean rainfall rate, and the fraction of rain area. The consideration of the kinematics and CG lightning flashes of convective systems and the knowledge of their life cycle stage demonstrate a potential for drawing information useful in rain rate retrievals and their variability.