衡阳新一代天气雷达多观测模式切换策略与阈值研究

Research on the Multi-Observation Mode Switching Strategy and Thresholds for the Hengyang New-Generation Weather Radar

摘要: 利用地面气象观测、闪电定位资料、雷达基数据及多观测模式运行日志，分析了衡阳新一代天气雷达2025年1月~2026年6月多观测模式运行的切换现状，并基于雷暴大风和短时强降水灾害样本对切换阈值进行本地化优化，探讨了运行切换机制。结果表明：1) 运行期间系统共产生VCP11智能提醒切换建议25,452条，按提示时间间隔 ≥ 60 min聚类为387次独立事件，其中2 h内命中雷暴大风或短时强降水的正确样本174次，正确率45%，反映出当前智能提醒存在预报员参与度偏低、误触发偏多的问题。2) 触发VCP11切换的关键因子为A2 ≥ 100 km²与A_VIL ≥ 10 km²；其中A2是主导触发条件。3) 建议将CR基础判别阈值由35 dBZ上调至40 dBZ；A2维持 ≥ 100 km²作为主触发条件，A_ET (回波顶高 ≥ 6 km面积)判定阈值由15km²下调至12 km² (4~9月ET阈值由6km提高至12 km、10~3月保持6 km)；VIL阈值由15 kg/m²下调至10 kg/m²，AVIL ≥ 10 km²作为辅助判据；并建议建立“天气形势研判 + 手动切换”与“智能提醒 + 人工判定”双轨切换机制。

Abstract: Based on surface meteorological observations, lightning location data, radar base data, and multi-observation mode operation logs, this study analyzes the current status of observation mode switching for the new-generation weather radar in Hengyang from January 2025 to June 2026, localizes and optimizes the switching thresholds using disaster samples of thunderstorm gales and short-duration heavy precipitation, and discusses the operational switching mechanism. The results show that: 1) During the operation period, the system generated a total of 25,452 VCP11 intelligent-reminder switching suggestions, which were clustered into 387 independent events with a prompt interval ≥ 60 min; among them, 174 were correct samples that hit thunderstorm gales or short-duration heavy precipitation within 2h, with a correct rate of 45%, reflecting that the current intelligent reminders suffer from low forecaster participation and excessive false triggers. 2) The key factors triggering VCP11 switching are A2 ≥ 100 km² and AVIL ≥ 10 km², among which A2 is the dominant triggering condition. 3) It is recommended to raise the CR basic discrimination threshold from 35 dBZ to 40 dBZ; maintain A2 ≥ 100 km² as the main triggering condition, and lower the A_ET (echo top height ≥ 6 km area) discrimination threshold from 15 km² to 12 km² (the ET threshold is raised from 6 km to 12 km from April to September and kept at 6 km from October to March); lower the VIL threshold from 15 kg/m² to 10 kg/m², with A_VIL ≥ 10 km² as an auxiliary criterion; and it is suggested to establish a dual-track switching mechanism of “weather situation analysis + manual switching” and “intelligent reminder + human judgment”.