Echo Feature Identification for Short-time Heavy Precipitation with S-band Observations

Abstract

Short-time heavy precipitation refers to a weather phenomenon in which the precipitation intensity is somewhat large in a short time, or the rainfall reaches or exceeds a certain value in the specified short time of period, which is an important indicator to evaluate the occurrence of severe convective weather. To address a process of precipitation in Beijing area, this paper studies the characteristics of weather radar echo under the condition of short-time heavy precipitation by using the ground rainfall observation from automatic weather station (AWS) network and the observations from the CINRAD-SA radar in Beijing area. A comparative analysis of a short-time heavy rainfall in Beijing area is conducted based on surface gauge and radar observations to investigate the temporal, spatial distributions of precipitation and the characteristics of radar echo above the surface stations, and the cross validation of AWS and SA radar data are carried out as well. For rainfall accumulation in 6min, the characteristics of ground precipitation were analyzed. Then, the consistency of radar products and ground precipitation characteristics were studied by analyzing the echo structure and its motion feature and matching quantitative precipitation estimation (QPE) products with surface rainfall observation. The result shows that the temporal and spatial distribution of short-time heavy precipitation have greater uncertainty, however, weather radar echo can reflect the characteristics of short-term heavy precipitation on the ground to a certain extent, and under the condition of short-term heavy precipitation, S-band radar QPE has a good consistency with the precipitation observed on the ground.