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Abstract The National Science Foundation–sponsored Lake-Effect Electrification (LEE) field campaign intensive observation periods occurred between November and early February 2022–23 across the eastern Lake Ontario region. Project LEE documented, for the first time, the total lightning and electrical charge structures of lake-effect storms and the associated storm environment using a lightning mapping array (LMA), a mobile dual-polarization X-band radar, and balloon-based soundings that measured vertical profiles of temperature, humidity, wind, electric field, and hydrometeor types. LEE also observed abundant wind turbine-initiated lightning, which is climatologically more likely during the winter. The frequent occurrence of intense lake-effect storms and the proximity of a wind farm with nearly 300 turbines each more than 100 m tall to the lee of Lake Ontario provided an ideal laboratory for this study. The field project involved many undergraduate (>20) and graduate students. Some foreseen and unforeseen challenges included clearing the LMA solar panels of snow and continuous operation in low-sunlight conditions, large sonde balloons prematurely popping due to extremely cold conditions, sonde line breaking, recovering probes in deep snow in heavily forested areas, vehicles getting stuck in the snowpack, and an abnormally dry season for parts of the LEE domain. In spite of these difficulties, a dataset was collected in multiple lake-effect snowstorms (11 observation periods) and one extratropical cyclone snowstorm that clarifies the electrical structure of these systems. A key finding was the existence of a near-surface substantial positive charge layer (1 nC m⁻³) near the shoreline during lake-effect thunderstorms. 

Abstract Tropical cyclone (TC) tornadoes are often associated with lower‐skill forecasts compared to midlatitude supercellular tornadoes. Forecasts may be improved through a greater understanding of their lightning and radar signatures. This study investigates the lightning and radar characteristics of TC tornadic cells for comparison with TC non‐tornadic cells (i.e., strongly rotating cells without tornadoes) and non‐TC tornadic cells using three lightning networks and radar data. These results show that the majority of TC tornadic and non‐tornadic cells are not associated with lightning, although the former subset occurs with lightning more often. TC tornadic cases typically have lightning maximized to its northeast, whereas the non‐tornadic subset is associated with a lower density of flashes that are more symmetrically distributed. TC tornadic mesocyclones also show stronger low‐level rotation and convergence at the time of tornado occurrence compared to non‐tornadic cases. Hourly trends in rotation and convergence show stronger increases before tornado occurrence in both variables for TC tornadic mesocyclones, yielding small, nonsignificant differences with non‐TC tornadic mesocyclones during tornado occurrence. Finally, analysis of lightning throughout the TC shows that tornadic cells often occur on the downwind edge of a broad lightning maximum, whereas non‐tornadic cases occur in the middle of a weaker lightning maximum, with these maxima propagating away from the TC in both subsets.