Abstract Based on multi-source high-resolution observational data, this study examines the spatiotemporal characteristics of winter lightning events in Ishikawa Prefecture, Japan (December 10–20, 2021), and their relationships with precipitable water vapor (PWV), surface temperature, and radar-derived precipitation intensity. By integrating time-series trend analysis, correlation tests, event-aligned averaging, and typical day comparisons, this study offers insights into lightning activity and associated environmental responses. In this case study, lightning tended to occur more frequently at night and along coastal areas; however, as the dataset is limited to a short winter period, these tendencies may partly reflect large-scale disturbances such as cold fronts or monsoonal cold air intrusions. Radar-derived precipitation intensity aligned most closely with lightning, typically strengthening just before or in step with peaks, reflecting the role of convective precipitation. PWV appeared to act as an important moisture-related indicator: elevated PWV values sometimes coincided with or slightly preceded lightning-active periods, suggesting that PWV may provide information on the background moisture conditions associated with winter lightning episodes, although longer-term validation is needed. Surface temperature provided a secondary thermal background, with lightning often associated with relatively warm phases before outbreaks and cooling afterward, possibly due to both cold air intrusions and thundercloud passage. Comparative analyses of high-, medium-, and low-frequency days indicated that frequent lightning outbreaks were more likely when abundant PWV, favorable thermal conditions, and strong convective precipitation occurred together, whereas any single factor alone was insufficient. These findings highlight the environmental conditions associated with winter lightning in Hokuriku and provide preliminary insights that may support future regional early-warning studies.
Wang et al. (Tue,) studied this question.