Application of a Three-Dimensional Wind Field from a Phased-Array Weather Radar Network in Severe Convection Weather

In 2019-2020, an array weather radar (AWR) network consisting of seven X-band phased-array radars (PARs), with a detection spatial resolution of 30 m and a temporal resolution of 30 s, was built in the city of Foshan in China's Guangdong Province. The detection time deviation in the same space is within 5 s. Through variational data assimilation, the three-dimensional wind field inside the storm can be obtained. This study selected instances of hail, thunderstorms, strong winds, and short-duration heavy precipitation in 2020 to conduct a detailed analysis. The results show the following: (1) The fine detection ability enables phased-array radars to detect the complete evolution process of convective storms, including development, strengthening, and weakening, providing a useful reference for judging the future variation trends of convective storms. (2) Through evolutionary analysis of the three-dimensional wind field, the dynamic mechanisms of storm strengthening and weakening could be obtained, which could serve as a reference to predict the development of storms. The gust wind index and convection index calculated based on the three-dimensional wind field could provide advanced warning for nowcasting. When the gust wind index was greater than 263, the probability of gale-force wind (above 17.0 m/s) was determined to be high. Moreover, the warning could be provided 10-20 min in advance. A convection index greater than 35 and the presence of concentrated contour lines were found to be conducive to the strengthening and formation of a convection, and the warning could be provided 20 min in advance. These results show that the application of PAR can provide important technical support for nowcasting severe convective weather.

Automated summary

An array weather radar (AWR) network with seven X-band phased-array radars was built in Foshan, Guangdong Province, China. The radar system has high spatial and temporal resolutions, allowing for the detection and analysis of convective storms such as hail, thunderstorms, strong winds, and heavy precipitation. The results show that the phased-array radars can accurately detect the evolution process of storms, providing valuable information for predicting future trends. The three-dimensional wind field analysis provides insights into the dynamic mechanisms of storm strengthening and weakening, enabling advanced warning for severe weather events.