Severe weather events are responsible for hundreds of fatalities and millions of euros of damage every year in the Mediterranean basin. Lightning activity is a characteristic phenomenon of severe weather and often accompanies torrential rainfall, which under certain conditions like terrain type, slope, drainage and soil saturation can generate flash flood. Therefore, the improvement in forecast skill for those high impact weather events is one of the main challenges in early warning systems. On the line of this need the behavior of the Lightning Potential Index (LPI) is evaluated in different case studies involving complex terrain. Such index represents a measure of the potential for charge generation and separation that lead to total lightning occurrence in clouds (both IC and CG).