The Hong Kong Observatory set up a lightning location system in 2005 to monitor lightning activities over Hong Kong and its neighbouring regions round the clock. The system comprises a total of six low-frequency sensors which are capable of detecting cloud-to-ground and cloud lightning. The Observatory disseminates the lightning information through various channels, providing different types of services to the public, the business and industry sectors.

Embracing both Internet and Geographic Information System (GIS) technologies, the Observatory provides near-real-time lightning location information graphically on its website. A user-friendly decision making tool allows users to select their own location of interest and the webpage will automatically provide alerts when lightning strokes are detected within a 15 km range. Users can choose their location of interest either from the popular places listed on the webpage or by entering the name of a building, estate or street. They can also click directly on the lightning map to specify the place of concern. The lightning alerting tool allows users to make conscious decisions based on the assessment of weather situation. Examples abound. Operators of swimming pools can keep their pools open when the tool indicates that lightning poses no immediate threat to the pool and its vicinity, even though there may be lightning affecting other parts of the territory. In the 2008 Olympic and Paralympic Equestrian Events in Hong Kong, the tool provides real-time site-specific lightning information to the event organizers, enabling them to better arrange the game schedule in the event of thundery weather. The details of these and other applications will be discussed in the full paper and the presentation at the conference.