Characteristics of Negative Cloud‐To‐Ground Lightning Flashes Associated With Their Peak Currents of First Return Strokes

This study investigates the characteristics of negative cloud‐to‐ground (CG) lightning flashes across varying peak current (PCs) ranges by combining 3D location data from 2,597 negative CG flashes with radar observations. The flashes were classified into five PC bins: −25 kA < PC < 0 kA, −50 kA < PC < −25 kA, −75 kA < PC ≤ −50 kA, −100 kA < PC ≤ −75 kA, and PC ≤ −100 kA. Key parameters analyzed include initiation altitude, reflectivity at initiation points, vertical reflectivity cores, lightning extension spaces, horizontal distances between initiation and grounding points (HD), and time differences between the first‐detected radiation source and the first return stroke (TD). Results reveal that while initiation environments were broadly similar across PC ranges, large‐PC flashes tended to initiate at lower altitudes (1–3 km). These flashes form first return strokes faster (the median TD for current bins below −75 kA is less than 44 ms, whereas for bins above −75 kA the median TD is greater than 57 ms) after shorter horizontal propagation (The median HD for current bins below −75 kA is around 1.0 km, while for bins above −75 kA the median HD exceeds 1.2 km), with smaller pre‐return‐stroke extension areas. Despite this, large‐PC flashes usually develop more extensive total channel areas. These findings underscore the distinct environmental conditions that facilitate the initiation and propagation of large‐PC negative CG flashes during thunderstorms.