Abstract & Overview
The Lake Maracaibo basin (LM) and its surrounding valley constitute a distinctive geo-atmospheric system that supports one of the highest lightning densities on Earth. The basin is connected to the Caribbean Sea through the Gulf of Venezuela, allowing persistent exchanges of moisture and heat between marine and continental air masses. The LM exhibits the highest frequency of thunderstorm-related lightning activity on Earth, with approximately 300 thunderstorm days per year. Previous observations have consistently identified two major lightning-activity hotspots: one over the southwestern sector of Lake Maracaibo (C1) and another over the adjacent mountainous terrain (C2). Both centers exhibit pronounced nocturnal variability, with a systematic time lag of several hours between their respective activity maxima. This work synthesizes previous observational evidence and proposes a conceptual model to explain the spatial and temporal organization of deep convection and lightning activity in the region. The model provides a physical explanation for (i) the different times of maximum convective and lightning activity in the two main centers, C2 and C1, (ii) the systematic time lag between these two regions, and (iii) the spatial confinement and persistence of the strongest lightning activity. The model proposes that moisture transport associated with the Caribbean Low-Level Jet, its accumulation over the warm lake, orographic lifting near the surrounding mountains, and the subsequent propagation of convective outflows toward the lake interact in a specific sequence. This sequence favors the development of convection first near C2 and subsequently over C1, where the outflows interact with the warm, moisture-rich air accumulated over the lake, promoting the initiation or intensification of convection during the late-night hours.