Nowcasting of High-Intensity Rainfall for Urban Applications in the Netherlands

作者：Guo-Shiuan Lin, Ruben Imhoff, Marc Schleiss, R. Uijlenhoet · 发表于：Journal of Hydrometeorology · 年份：2024 · DOI：10.1175/jhm-d-23-0194.1 · 被引用次数：6 · 研究领域：Precipitation Measurement and Analysis、3D Modeling in Geospatial Applications、Evacuation and Crowd Dynamics

Abstract Radar rainfall nowcasting has mostly been applied to relatively large (often rural) domains (e.g., river basins), although rainfall nowcasting in small urban areas is expected to be more challenging. Here, we selected 80 events with high rainfall intensities (at least one 1-km 2 grid cell experiences precipitation >15 mm h −1 for 1-h events or 30 mm day −1 for 24-h events) in five urban areas (Maastricht, Eindhoven, The Hague, Amsterdam, and Groningen) in the Netherlands. We evaluated the performance of 9060 probabilistic nowcasts with 20 ensemble members by applying the short-term ensemble prediction system (STEPS) from Pysteps to every 10-min issue time for the selected events. We found that nowcast errors increased with decreasing (urban) areas especially when below 100 km 2 . In addition, at 30-min lead time, the underestimation of nowcasts was 38% larger and the discrimination ability was 11% lower for 1-h events than for 24-h events. A set of gridded correction factors for the Netherlands, CARROTS (Climatology-based Adjustments for Radar Rainfall in an Operational Setting) could adjust the bias in real-time QPE and nowcasts by 70%. Yet, nowcasts were still found to underestimate rainfall more than 50% above 40-min lead time relative to the reference, which indicates that this error originates from the nowcasting model itself. Also, CARROTS did not adjust the rainfall spatial distribution in urban areas much. In summary, radar-based nowcasting for urban areas...