Lightning Initiation and Intensity Nowcasting based on Isothermal Radar Reflectivity—A Conceptual Model

Intense convective activity associated with summer monsoon, monsoon troughs and tropical cyclones poses a major weather threat in the warm seasons of Hong Kong. Very often, such intense convective activity will also trigger other types of hazardous weathers. As shown in Table I, lightning strikes, heavy rainstorms, damaging downbursts/squalls, hails, waterspouts and even tornadoes are not uncommon in Hong Kong. In terms of occurrence frequencies as shown in Table I, thunderstorm lightning is actually the most frequent type of weather hazard in Hong Kong. At the Hong Kong Observatory (HKO), a second generation nowcasting system is currently under development to track and nowcast such severe weather phenomena. For more details on SWIRLS (Short-range Warning of Intense Rainstorms in Localized Systems ), readers are referred to Li and Lai 2004.