深圳机场一次水龙卷过程的预报技术研讨
Discussion on the Forecasting Techniques for a Water Tornado Process in Shenzhen Airport

本文针对预报漏报的深圳机场2024年8月12日早间周边海域水龙卷过程，从雷达特征及触发条件开展分析发现，该水龙卷水平尺度较小，为百米级别，强度偏弱，需综合使用相控阵雷达对特定的钩状回波进行识别。此外，水龙卷由于垂直发展高度及云底高度较低，在雷达规划时需考虑土建海拔高度，并合理使用不同仰角扫描产品，避免龙卷特征出现在雷达高度以下。本次过程由弱暖区西南气流增长提供动力抬升，配合强烈能量释放形成强对流，同时叠加超过28 m/s的强低层风切变和底层涡旋触发出水龙卷。在短期预报中，低层垂直风切变、相对螺旋度等指标较难指示出水龙卷发生的可能性，但在临近预报中可重点关注上游风廓线雷达，可提供近1小时提前量，有利于及早开展短临预警。
In this paper, for the water tornado process in the surrounding waters of Shenzhen Airport in the morning of August 12, 2024, which was not reported in the operational forecast, the radar characteristics and trigger conditions were detailed analyzed. It was found that the horizontal scale of the water tornado was small with the level of 100 meters, and the intensity was weak, so the special characteristic of hook echo in tornado should be recognized by the phased array radar. In addition, due to the low vertical development height and cloud base height of water tornado, it is necessary to consider the altitude for the radar design, and reasonably use different elevation scanning products to avoid the occurrence of tornado features below the radar altitude. This process is triggered by the growth of southwesterly in the weakly warm region, combined with the strong energy release to form strong convection. At the same time, the low-level vertical wind shear exceeding 28 m/s and the bottom vortex trigger the water tornado. In short-term forecasting, low-level vertical wind shear, relative helicity and other indicators are difficult to indicate the possibility of a water tornado, but in the near-term forecasting, we can focus on the upstream wind profile radar, which can provide nearly an hour in advance, and carry out the imminent early warning in time.