Observatory enhances lightning alert service

5 June 2009

The Observatory has today (June 5) enhanced its location-specific lightning alert webpage. With the number of alert circles increased from one to three, the webpage can now provide different levels of alert depending on the distance of lightning.This helps people engaging in outdoor activities to make suitable arrangements under different situations.

With the launch of the new service today, users will have the flexibility to select up to three alert circles of different sizes, ranging from a minimum of five kilometres to a maximum of 50 kilometres.The new feature helps people engaging in outdoor activities or managing outdoor facilities to escalate the response level and take appropriate preventive measures as the lightning approaches.The enhanced service can be accessed on http://www.weather.gov.hk/wxinfo/llis/alert_index.htm.

Since its start in mid-2005, the lightning location information webpage has become more and more enriched in content and function.The Observatory launched the lightning alert service last year.People can select their own location of interest on the webpage using different platforms to receive automatic alerts when there is lightning within a certain distance.

President of The Hong Kong Association of Property Management Company, Mr Kendrew Leung, said, "The Observatory's lightning alert service is very useful.It helps property management personnel identify the area affected by lightning and decide more flexibly whether to open or close the swimming pools and the outdoor recreational facilities."The association has more than 80 company members.

The Observatory has also enhanced the lightning information webpage by providing a lightning density map of Hong Kong of the past few years (www.weather.gov.hk/wxinfo/llis/llis_map.htm).The information, which is updated every year, is useful to the engineering, construction and related sectors.

Vice-President of The Hong Kong Institute of Engineers, Ir Dr Chan Fuk-cheung, welcomed the new service provided by the Hong Kong Observatory."It enables engineers to easily obtain information on past lightning density and its distribution in Hong Kong for reference during the design of lightning protection systems.This helps improve the systems' effectiveness in protecting buildings and associated facilities against thunderstorms and lightning," Dr Chan said.

The lightning alert webpage provides three levels of alert

Number of cloud-to-ground lightning strokes per square kilometre per year during 2006 to 2008