Here is the current schedule for the Spring 2026 semester

 

 

Thunderstorm Charge Structure and Lightning: 
Application to Severe Weather Diagnosis

Bruno Medina (Texas Tech University)

Lightning occurs as a result of the kinematics and microphysics within thunderstorms. Updrafts lift hydrometeors to sub-freezing temperatures, leading to particle collisions and charge exchange. Large charge regions build up until sufficient electric potential exists for a lightning flash to occur. A rapid increase in the lightning flash rate indicates a surge in updraft strength, which is typically associated with severe storms that produce significant ground impacts, such as strong wind gusts and hail. The charge sign acquired by hydrometeor particles (in this case, graupel and ice crystals) after collisions depends on the temperature and liquid water content in the storm, influencing the storm’s overall charge structure. Most thunderstorms exhibit a positive charge layer near the cloud top and a negative charge layer in the mixed-phase region, a configuration known as a normal charge structure. In contrast, storms with positive charge in the mixed-phase region are referred to as anomalous charge structure storms. Anomalous storms are often associated with severe weather, as they tend to have stronger updrafts. These updrafts lift supercooled liquid water into sub-freezing temperatures, contributing to the positive charging of graupel and the formation of a positive charge layer in the mixed-phase region. This study investigates charge structures and lightning within thunderstorms, their association with severe weather, and the conditions favoring each charge structure archetype, including environmental factors, cloud condensation nuclei concentration, and radar-inferred microphysical and kinematic processes. 

 

Zoom Link: https://nmtedu.zoom.us/j/97572348560pwd=OLHjHRLKVCeL1LnUsxGTFMLrDJagQv.1

Meeting Id: 975 7234 8560; Passcode: 677943