Preliminary Applications of a Solid-State C-Band Weather Radar in Hong Kong for the Monitoring of Intense Convective Weather

A solid-state C-band weather radar has been on a trial run in Hong Kong for around three months for detecting intense convective weather, particularly its features in the atmospheric boundary layer. It serves to supplement the long-range surveillance weather radars working at the mountain tops of Hong Kong, a city with rather hilly terrain. Through a number of case studies, this paper demonstrates the application values of the low-elevation angle scans of this weather radar in two major aspects, namely, construction of a three-dimensional wind field extending down to a height of 1 km above sea level, and detection of hail through comparison with ground reports. The wind field at lower altitudes, which could not be obtained before from the mountain-top weather radars alone, is found to provide timely alerts to squalls associated with rainbands (such as bow echoes) and to monitor orographic precipitation. In a hail event over the Pearl River Estuary, the low-elevation scans of the radar are found to detect the occurrence of hail consistent with ground reports. The estimated maximum hail sizes from this radar are also found to be generally comparable with the limited number of actual observations. With lower power consumption, the solid-state radar is more robust and may be deployed at more locations over Hong Kong, particularly the remote locations such as outlying islands and rural areas. It opens up the possibility of building a network of weather radars to monitor the atmospheric boundary layer conditions associated with intense convective weather in an area with hilly terrain.