RADAR-BASED STOCHASTIC PRECIPITATION NOWCASTING USING THE SHORT-TERM ENSEMBLE PREDICTION SYSTEM (STEPS) (CASE STUDY: PANGKALAN BUN WEATHER RADAR)
RADAR-BASED STOCHASTIC PRECIPITATION NOWCASTING USING THE SHORT-TERM ENSEMBLE PREDICTION SYSTEM (STEPS) (CASE STUDY: PANGKALAN BUN WEATHER RADAR)
复制标题
使用短期集合预报系统进行基于雷达的随机降水即时预报（步骤）（案例研究：PANGKALAN BUN 天气雷达）
DOI：
10.30536/j.ijreses.2021.v18.a3527
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Umi Sa’adah
中科院分区：
文献类型：
--
作者：
A. Ali;S. Supriatna;Umi Sa’adah
在水文气象灾害中，迫切需要临近预报或降水短期预报来支持缓解圈。庞卡兰堡气象雷达是最大探测距离为200公里的单极化雷达，10分钟内运行10个仰角，空间分辨率为250米。覆盖区域周围没有地形阻塞。短期集合预报系统（STEPS）是用于生成降水临近预报的众多算法之一，并且已经在实际应用中。STEPS的优点是产生集合的临近预报，通过它可以统计量化临近预报的不确定性。本研究旨在将STEPS应用于庞卡兰堡天气雷达随机临近预报，并分析其优缺点。通过计算5 dBZ阈值下的检测和假警报的可能性并将它们绘制在相对工作特性（ROC）曲线中来测量精度。观测频率和预报概率用可靠性图表示，以评价临近预报的可靠性和清晰度。定性分析结果表明，STEPS集合产生的平滑反射率场无法捕捉到观测到的准线性对流系统（QLCS）的极值，但该算法在使用的阈值（高达40分钟的提前时间）下获得了良好的精度。ROC显示了左上角的曲线，可靠性图是一条几乎完美的临近投影对角线。
Nowcasting, or the short-term forecasting of precipitation, is urgently needed to support the mitigation circle in hydrometeorological disasters. Pangkalan Bun weather radar is single-polarization radar with a 200 km maximum range and which runs 10 elevation angles in 10 minutes with a 250 meters spatial resolution. There is no terrain blocking around the covered area. The Short-Term Ensemble Prediction System (STEPS) is one of many algorithms that is used to generate precipitation nowcasting, and is already in operational use. STEPS has the advantage of producing ensemble nowcasts, by which nowcast uncertainties can be statistically quantified. This research aims to apply STEPS to generate stochastic nowcasting in Pangkalan Bun weather radar and to analyze its advantages and weaknesses. Accuracy is measured by counting the possibility of detection and false alarms under the 5 dBZ threshold and plotting them in a relative operating characteristic (ROC) curve. The observed frequency and forecast probability is represented by a reliability diagram to evaluate nowcast reliability and sharpness. Qualitative analysis of the results showed that the STEPS ensemble produces smoothed reflectivity fields that cannot capture extreme values in an observed quasi-linear convective system (QLCS), but that the algorithm achieves good accuracy under the threshold used, up to 40 minutes lead time. The ROC shows a curved upper left-hand corner, and the reliability diagram is an almost perfect nowcast diagonal line.