Lightning Legend
Notes:
  • C-to-g: Cloud to ground lightning location
    C-to-c: Cloud to cloud lightning location

  • The image shows cloud-to-ground or cloud-to-cloud lightning strokes as detected by the Lightning Location Network over the Pearl River Estuary in the past 30 minutes. The lightning records are updated at 5-minute intervals. Cloud-to-cloud lightning strokes are those detected strokes that did not reach the ground. As such, they might not affect people or facilities on the ground. However, it should be noted that they may sometimes precede cloud-to-ground strokes. The location as shown depicts roughly the starting point of the discharge from one cloud to the other.

  • The network comprises seven stations jointly established by the Hong Kong Observatory, the Guangdong Meteorological Bureau and the Macao Meteorological and Geophysical Bureau. The stations are located at Chung Hom Kok, Tsim Bei Tsui, Sha Tau Kok, Taipa in Macao, Sanshui, Huidong and Yangjiang in Guangdong. (Click here to see the location of these stations)

  • The accuracy in determining the location of cloud-to-ground lightning strokes is about 500 m within the network when all stations are operative. The lightning detection efficiency, i.e. the probability that a stroke with peak current greater than a certain level can be detected by the network, is estimated to be around 90 %. The location accuracy and detection efficiency will be reduced when the lightning stroke occurs outside of the network or when not all of the stations are operative. Since the lightning sensors are designed to detect mainly cloud-to-ground lightning, the efficiency of cloud-to-cloud lightning detection is not high and is estimated to range from 10% to 50%.

  • There is no guarantee that all occurred lightning strokes can be detected and false detection of lightning strokes cannot be ruled out completely. As it takes time for communication and computation, there is normally a delay of a few minutes in the display of data. Other factors, including interruption to telecommunications services and power supply, can also affect the reliability and availability of the lightning information.

  • For enquiries, please email to hkowm@hko.gov.hk

WeChat QR Codes:
Guangdong Meteorological Bureau Hong Kong Observatory Macao Meteorological and Geophysical Bureau