Application Analysis of Doppler Radar Characteristics Index Early Warning for Thunderstorm Gale in Langfang City
The gust front,high speed value area and other warning indicators were verified and analyzed by using Doppler weather radar in Beijing,Tianjin and Cangzhou during 29 thunderstorm gale weather processes in Langfang city from 2010 to 2019.The results showed that:The gust front appeared in 51.9％of the stations,and 61.0％of the thunderstorms appeared in the center to the right of the main echo moving ahead.The area with high wind speed above 17 m·s-1 on the radial velocity chart of 0.5° elevation angle was taken as the warning index,and the average advance of warning was 47.2 min.There was a high wind speed area above 17 m·s-1 in the upstream and possibly affected area before 100％bow echo thunderstorms appeared,so the early warning could be issued 37.1 min in advance.The average warning advance amount was the highest,reaching 52.7 min,in the 71.4％thunderstorm wind stations and areas where VIL was above 40 kg·m-2 within 10 km of thunderstorm stations.In 73.7％of the massive echo thunderstorms,there were large wind speed areas with radial velocity above 17 m·s-1 in the upstream and possibly affected areas.Combined with above 17 m·s-1 and above 20 m·s-1,gust front,and VIL above 40 kg·m-2 in the upstream and possible influence areas,thunderstorm gale warning signals can be issued 30-60 min in advance,and the falling area,occurrence time and intensity of catastrophic gale can be predicted more accurately.
万方数据
维普
